Last tested: 16 Jul, 2018

cordova vulnerabilities

Cordova command line interface tool

View on npm

cordova (latest)

Published 10 Jul, 2018

Known vulnerabilities5
Vulnerable paths23
Dependencies513

Uninitialized Memory Exposure

medium severity

Detailed paths

  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > request@2.79.0 > tunnel-agent@0.4.3

Overview

tunnel-agent is HTTP proxy tunneling agent. Affected versions of the package are vulnerable to Uninitialized Memory Exposure.

A possible memory disclosure vulnerability exists when a value of type number is used to set the proxy.auth option of a request request and results in a possible uninitialized memory exposures in the request body.

This is a result of unobstructed use of the Buffer constructor, whose insecure default constructor increases the odds of memory leakage.

Details

Constructing a Buffer class with integer N creates a Buffer of length N with raw (not "zero-ed") memory.

In the following example, the first call would allocate 100 bytes of memory, while the second example will allocate the memory needed for the string "100":

// uninitialized Buffer of length 100
x = new Buffer(100);
// initialized Buffer with value of '100'
x = new Buffer('100');

tunnel-agent's request construction uses the default Buffer constructor as-is, making it easy to append uninitialized memory to an existing list. If the value of the buffer list is exposed to users, it may expose raw server side memory, potentially holding secrets, private data and code. This is a similar vulnerability to the infamous Heartbleed flaw in OpenSSL.

Proof of concept by ChALkeR

require('request')({
  method: 'GET',
  uri: 'http://www.example.com',
  tunnel: true,
  proxy:{
      protocol: 'http:',
      host:"127.0.0.1",
      port:8080,
      auth:80
  }
});

You can read more about the insecure Buffer behavior on our blog.

Similar vulnerabilities were discovered in request, mongoose, ws and sequelize.

Remediation

Upgrade tunnel-agent to version 0.6.0 or higher. Note This is vulnerable only for Node <=4

References

Prototype Pollution

low severity

Detailed paths

  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > request@2.79.0 > hawk@3.1.3 > hoek@2.16.3
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > request@2.79.0 > hawk@3.1.3 > boom@2.10.1 > hoek@2.16.3
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > request@2.79.0 > hawk@3.1.3 > cryptiles@2.0.5 > boom@2.10.1 > hoek@2.16.3
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > request@2.79.0 > hawk@3.1.3 > sntp@1.0.9 > hoek@2.16.3

Overview

hoek is a Utility methods for the hapi ecosystem.

Affected versions of this package are vulnerable to Prototype Pollution. The utilities function allow modification of the Object prototype. If an attacker can control part of the structure passed to this function, they could add or modify an existing property.

PoC by Olivier Arteau (HoLyVieR)

var Hoek = require('hoek');
var malicious_payload = '{"__proto__":{"oops":"It works !"}}';

var a = {};
console.log("Before : " + a.oops);
Hoek.merge({}, JSON.parse(malicious_payload));
console.log("After : " + a.oops);

Remediation

Upgrade hoek to versions 4.2.1, 5.0.3 or higher.

References

Command Injection

high severity

Detailed paths

  • Introduced through: cordova@8.0.0 > cordova-common@2.2.5 > shelljs@0.5.3
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-common@2.2.5 > shelljs@0.5.3
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-create@1.1.2 > cordova-common@2.2.5 > shelljs@0.5.3
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-fetch@1.3.0 > cordova-common@2.2.5 > shelljs@0.5.3
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-create@1.1.2 > cordova-fetch@1.3.0 > cordova-common@2.2.5 > shelljs@0.5.3
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-serve@2.0.1 > shelljs@0.5.3
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-create@1.1.2 > shelljs@0.3.0
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > shelljs@0.3.0
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-fetch@1.3.0 > shelljs@0.7.8
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-create@1.1.2 > cordova-fetch@1.3.0 > shelljs@0.7.8

Overview

shelljs is a portable Unix shell commands for Node.js.

Affected version of this package are vulnerable to Command Injection. It is possible to invoke commands from shell.exec() from external sources, allowing an attacker to inject arbitrary commands.

Remediation

There is no fix version for shelljs.

References

Prototype Pollution

low severity

Detailed paths

  • Introduced through: cordova@8.0.0 > insight@0.8.4 > inquirer@0.10.1 > lodash@3.10.1

Overview

lodash is a javaScript utility library delivering modularity, performance & extras.

Affected versions of this package are vulnerable to Prototype Pollution. The utilities function allow modification of the Object prototype. If an attacker can control part of the structure passed to this function, they could add or modify an existing property.

PoC by Olivier Arteau (HoLyVieR)

var _= require('lodash');
var malicious_payload = '{"__proto__":{"oops":"It works !"}}';

var a = {};
console.log("Before : " + a.oops);
_.merge({}, JSON.parse(malicious_payload));
console.log("After : " + a.oops);

Remediation

Upgrade lodash to version 4.17.5 or higher.

References

Regular Expression Denial of Service (ReDoS)

low severity

Detailed paths

  • Introduced through: cordova@8.0.0 > cordova-common@2.2.5 > plist@2.1.0
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-common@2.2.5 > plist@2.1.0
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-create@1.1.2 > cordova-common@2.2.5 > plist@2.1.0
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-fetch@1.3.0 > cordova-common@2.2.5 > plist@2.1.0
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > cordova-create@1.1.2 > cordova-fetch@1.3.0 > cordova-common@2.2.5 > plist@2.1.0
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > plist@2.0.1
  • Introduced through: cordova@8.0.0 > cordova-lib@8.0.0 > xcode@1.0.0 > simple-plist@0.2.1 > plist@2.0.1

Overview

plist is a Mac OS X Plist parser/builder for Node.js and browsers

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks due to bundling a vulnerable version of the XMLBuilder package. This can cause an impact of about 10 seconds matching time for data 60 characters long.

Disclosure Timeline

  • Feb 5th, 2018 - Initial Disclosure to package owner
  • Feb 6th, 2018 - Initial Response from package owner
  • Mar 18th, 2018 - Fix issued
  • Apr 15th, 2018 - Vulnerability published

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade plist to version 3.0.1 or higher.

References

Vulnerable versions of cordova

Fixed in 8.0.1-nightly.2018.5.5.aeb1ddbc

Prototype Pollution

low severity

Detailed paths

  • Introduced through: cordova@8.0.1-nightly.2018.5.2.aeb1ddbc > cordova-lib@8.0.1-nightly.2018.5.2.fc69a0bd > request@2.79.0 > hawk@3.1.3 > hoek@2.16.3
  • Introduced through: cordova@8.0.1-nightly.2018.5.2.aeb1ddbc > cordova-lib@8.0.1-nightly.2018.5.2.fc69a0bd > request@2.79.0 > hawk@3.1.3 > boom@2.10.1 > hoek@2.16.3
  • Introduced through: cordova@8.0.1-nightly.2018.5.2.aeb1ddbc > cordova-lib@8.0.1-nightly.2018.5.2.fc69a0bd > request@2.79.0 > hawk@3.1.3 > cryptiles@2.0.5 > boom@2.10.1 > hoek@2.16.3
  • Introduced through: cordova@8.0.1-nightly.2018.5.2.aeb1ddbc > cordova-lib@8.0.1-nightly.2018.5.2.fc69a0bd > request@2.79.0 > hawk@3.1.3 > sntp@1.0.9 > hoek@2.16.3

Overview

hoek is a Utility methods for the hapi ecosystem.

Affected versions of this package are vulnerable to Prototype Pollution. The utilities function allow modification of the Object prototype. If an attacker can control part of the structure passed to this function, they could add or modify an existing property.

PoC by Olivier Arteau (HoLyVieR)

var Hoek = require('hoek');
var malicious_payload = '{"__proto__":{"oops":"It works !"}}';

var a = {};
console.log("Before : " + a.oops);
Hoek.merge({}, JSON.parse(malicious_payload));
console.log("After : " + a.oops);

Remediation

Upgrade hoek to versions 4.2.1, 5.0.3 or higher.

References

Uninitialized Memory Exposure

medium severity

Detailed paths

  • Introduced through: cordova@8.0.1-nightly.2018.5.2.aeb1ddbc > cordova-lib@8.0.1-nightly.2018.5.2.fc69a0bd > request@2.79.0 > tunnel-agent@0.4.3

Overview

tunnel-agent is HTTP proxy tunneling agent. Affected versions of the package are vulnerable to Uninitialized Memory Exposure.

A possible memory disclosure vulnerability exists when a value of type number is used to set the proxy.auth option of a request request and results in a possible uninitialized memory exposures in the request body.

This is a result of unobstructed use of the Buffer constructor, whose insecure default constructor increases the odds of memory leakage.

Details

Constructing a Buffer class with integer N creates a Buffer of length N with raw (not "zero-ed") memory.

In the following example, the first call would allocate 100 bytes of memory, while the second example will allocate the memory needed for the string "100":

// uninitialized Buffer of length 100
x = new Buffer(100);
// initialized Buffer with value of '100'
x = new Buffer('100');

tunnel-agent's request construction uses the default Buffer constructor as-is, making it easy to append uninitialized memory to an existing list. If the value of the buffer list is exposed to users, it may expose raw server side memory, potentially holding secrets, private data and code. This is a similar vulnerability to the infamous Heartbleed flaw in OpenSSL.

Proof of concept by ChALkeR

require('request')({
  method: 'GET',
  uri: 'http://www.example.com',
  tunnel: true,
  proxy:{
      protocol: 'http:',
      host:"127.0.0.1",
      port:8080,
      auth:80
  }
});

You can read more about the insecure Buffer behavior on our blog.

Similar vulnerabilities were discovered in request, mongoose, ws and sequelize.

Remediation

Upgrade tunnel-agent to version 0.6.0 or higher. Note This is vulnerable only for Node <=4

References

Fixed in 7.1.1-nightly.2017.12.14.ffa51bc1

Access Restriction Bypass

medium severity

Detailed paths

  • Introduced through: cordova@7.1.1-nightly.2017.12.12.8262ae29 > cordova-lib@7.1.1-nightly.2017.12.12.3109e4fe > npm@2.15.12

Overview

npm is a JavaScript package manager.

Affected versions of this package are vulnerable to Access Restriction Bypass. It might allow local users to bypass intended filesystem access restrictions due to ownerships of /etc and /usr directories are being changed unexpectedly, related to a "correctMkdir" issue.

Remediation

Upgrade npm to version 5.7.1 or higher.

References

Fixed in 6.5.1-nightly.2017.3.25.035d86c6

Remote Memory Exposure

medium severity

Detailed paths

  • Introduced through: cordova@6.5.1-nightly.2017.3.24.035d86c6 > cordova-lib@6.5.1-nightly.2017.3.24.00341c04 > request@2.47.0

Overview

request is a simplified http request client. A potential remote memory exposure vulnerability exists in request. If a request uses a multipart attachment and the body type option is number with value X, then X bytes of uninitialized memory will be sent in the body of the request.

Note that while the impact of this vulnerability is high (memory exposure), exploiting it is likely difficult, as the attacker needs to somehow control the body type of the request. One potential exploit scenario is when a request is composed based on JSON input, including the body type, allowing a malicious JSON to trigger the memory leak.

Details

Constructing a Buffer class with integer N creates a Buffer of length N with non zero-ed out memory. Example:

var x = new Buffer(100); // uninitialized Buffer of length 100
// vs
var x = new Buffer('100'); // initialized Buffer with value of '100'

Initializing a multipart body in such manner will cause uninitialized memory to be sent in the body of the request.

Proof of concept

var http = require('http')
var request = require('request')

http.createServer(function (req, res) {
  var data = ''
  req.setEncoding('utf8')
  req.on('data', function (chunk) {
    console.log('data')
    data += chunk
  })
  req.on('end', function () {
    // this will print uninitialized memory from the client
    console.log('Client sent:\n', data)
  })
  res.end()
}).listen(8000)

request({
  method: 'POST',
  uri: 'http://localhost:8000',
  multipart: [{ body: 1000 }]
},
function (err, res, body) {
  if (err) return console.error('upload failed:', err)
  console.log('sent')
})

Remediation

Upgrade request to version 2.68.0 or higher.

If a direct dependency update is not possible, use snyk wizard to patch this vulnerability.

References

Timing Attack

medium severity

Detailed paths

  • Introduced through: cordova@6.5.1-nightly.2017.3.24.035d86c6 > cordova-lib@6.5.1-nightly.2017.3.24.00341c04 > request@2.47.0 > http-signature@0.10.1

Overview

http-signature is a reference implementation of Joyent's HTTP Signature scheme.

Affected versions of the package are vulnerable to Timing Attacks due to time-variable comparison of signatures.

The library implemented a character to character comparison, similar to the built-in string comparison mechanism, ===, and not a time constant string comparison. As a result, the comparison will fail faster when the first characters in the signature are incorrect. An attacker can use this difference to perform a timing attack, essentially allowing them to guess the signature one character at a time.

You can read more about timing attacks in Node.js on the Snyk blog.

Remediation

Upgrade http-signature to version 1.0.0 or higher.

References

Regular Expression Denial of Service (DoS)

low severity

Detailed paths

  • Introduced through: cordova@6.5.1-nightly.2017.3.24.035d86c6 > cordova-lib@6.5.1-nightly.2017.3.24.00341c04 > request@2.47.0 > hawk@1.1.1

Overview

hawk is an HTTP authentication scheme using a message authentication code (MAC) algorithm to provide partial HTTP request cryptographic verification.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

You can read more about Regular Expression Denial of Service (ReDoS) on our blog.

References

Prototype Override Protection Bypass

high severity

Detailed paths

  • Introduced through: cordova@6.5.1-nightly.2017.3.24.035d86c6 > cordova-lib@6.5.1-nightly.2017.3.24.00341c04 > request@2.47.0 > qs@2.3.3

Overview

qs is a querystring parser that supports nesting and arrays, with a depth limit.

By default qs protects against attacks that attempt to overwrite an object's existing prototype properties, such as toString(), hasOwnProperty(),etc.

From qs documentation:

By default parameters that would overwrite properties on the object prototype are ignored, if you wish to keep the data from those fields either use plainObjects as mentioned above, or set allowPrototypes to true which will allow user input to overwrite those properties. WARNING It is generally a bad idea to enable this option as it can cause problems when attempting to use the properties that have been overwritten. Always be careful with this option.

Overwriting these properties can impact application logic, potentially allowing attackers to work around security controls, modify data, make the application unstable and more.

In versions of the package affected by this vulnerability, it is possible to circumvent this protection and overwrite prototype properties and functions by prefixing the name of the parameter with [ or ]. e.g. qs.parse("]=toString") will return {toString = true}, as a result, calling toString() on the object will throw an exception.

Example:

qs.parse('toString=foo', { allowPrototypes: false })
// {}

qs.parse("]=toString", { allowPrototypes: false })
// {toString = true} <== prototype overwritten

For more information, you can check out our blog.

Disclosure Timeline

  • February 13th, 2017 - Reported the issue to package owner.
  • February 13th, 2017 - Issue acknowledged by package owner.
  • February 16th, 2017 - Partial fix released in versions 6.0.3, 6.1.1, 6.2.2, 6.3.1.
  • March 6th, 2017 - Final fix released in versions 6.4.0,6.3.2, 6.2.3, 6.1.2 and 6.0.4

Remediation

Upgrade qs to version 6.4.0 or higher. Note: The fix was backported to the following versions 6.3.2, 6.2.3, 6.1.2, 6.0.4.

References

Regular Expression Denial of Service (ReDoS)

low severity

Detailed paths

  • Introduced through: cordova@6.5.1-nightly.2017.3.24.035d86c6 > cordova-lib@6.5.1-nightly.2017.3.24.00341c04 > request@2.47.0 > form-data@0.1.4 > mime@1.2.11

Overview

mime is a comprehensive, compact MIME type module.

Affected versions of this package are vulnerable to Regular expression Denial of Service (ReDoS). It uses regex the following regex /.*[\.\/\\]/ in its lookup, which can cause a slowdown of 2 seconds for 50k characters.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Many Regular Expression implementations may reach extreme situations that cause them to work very slowly (exponentially related to input size), allowing an attacker to exploit this and can cause the program to enter these extreme situations by using a specially crafted input and cause the service to excessively consume CPU, resulting in a Denial of Service.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade mime to versions 1.4.1, 2.0.3 or higher.

References

Fixed in 6.5.1-nightly.2017.3.12.f1e9e049

Symlink File Overwrite

high severity

Detailed paths

  • Introduced through: cordova@6.5.1-nightly.2017.3.10.f1e9e049 > cordova-lib@6.5.1-nightly.2017.3.10.30c4261e > tar@1.0.2

Overview

The tar module prior to version 2.0.0 does not properly normalize symbolic links pointing to targets outside the extraction root. As a result, packages may hold symbolic links to parent and sibling directories and overwrite those files when the package is extracted.

Remediation

Upgrade to version 2.0.0 or greater. If a direct dependency update is not possible, use snyk wizard to patch this vulnerability.

References

Fixed in 6.4.1-nightly.2016.10.25.c5977c97

Command Injection

high severity

Detailed paths

  • Introduced through: cordova@6.4.0-nightly.2016.10.22.576c8426 > cordova-lib@6.4.0-nightly.2016.10.22.4def2b3e > cordova-js@4.1.4 > browserify@10.1.3 > shell-quote@0.0.1

Overview

shell-quote is an npm package used to quote and parse shell commands. The quote function does not properly escape the following special characters <, >, ;, {, } , and as a result can be used by an attacker to inject malicious shell commands or leak sensitive information.

Shell command injection proof of concept

Consider the following poc.js application

var quote = require('shell-quote').quote;
var exec = require('child_process').exec;

var userInput = process.argv[2];

var safeCommand = quote(['echo', userInput]);

exec(safeCommand, function (err, stdout, stderr) {
  console.log(stdout);
});

Running the following command will not only print the character a as expected, but will also run the another command, i.e touch malicious.sh

$ node poc.js 'a;{touch,malicious.sh}'

Remediation

Upgrade shell-quote to version 1.6.1 or greater.

References

Regular Expression Denial of Service (DoS)

high severity

Detailed paths

  • Introduced through: cordova@6.4.0-nightly.2016.10.22.576c8426 > cordova-lib@6.4.0-nightly.2016.10.22.4def2b3e > cordova-js@4.1.4 > browserify@10.1.3 > glob@4.5.3 > minimatch@2.0.10

Overview

minimatch is a minimalistic matching library used for converting glob expressions into JavaScript RegExp objects. Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Many Regular Expression implementations may reach edge cases that causes them to work very slowly (exponentially related to input size), allowing an attacker to exploit this and can cause the program to enter these extreme situations by using a specially crafted input and cause the service to excessively consume CPU, resulting in a Denial of Service.

An attacker can provide a long value to the minimatch function, which nearly matches the pattern being matched. This will cause the regular expression matching to take a long time, all the while occupying the event loop and preventing it from processing other requests and making the server unavailable (a Denial of Service attack).

You can read more about Regular Expression Denial of Service (ReDoS) on our blog.

Remediation

Upgrade minimatch to version 3.0.2 or greater.

References

Fixed in 6.2.0

Insecure Randomness

medium severity

Detailed paths

  • Introduced through: cordova@6.1.1 > cordova-lib@6.1.1 > xcode@0.8.0 > node-uuid@1.3.3

Overview

node-uuid is a Simple, fast generation of RFC4122 UUIDS.

Affected versions of this package are vulnerable to Insecure Randomness. It uses the cryptographically insecure Math.random which can produce predictable values and should not be used in security-sensitive context.

Remediation

Upgrade node-uuid to version 1.4.4 or greater.

References

Fixed in 6.0.0

Prototype Pollution

low severity

Detailed paths

  • Introduced through: cordova@5.4.1 > cordova-lib@5.4.1 > rc@0.5.2 > deep-extend@0.2.11

Overview

Affected versions of deep-extend are vulnerable to Prototype Pollution. Utilities function in all the listed modules can be tricked into modifying the prototype of "Object" when the attacker control part of the structure passed to these function. This can let an attacker add or modify existing property that will exist on all object.

PoC by HoLyVieR

var merge = require('deep-extend');
var malicious_payload = '{"__proto__":{"oops":"It works !"}}';

var a = {};
console.log("Before : " + a.oops);
merge({}, JSON.parse(malicious_payload));
console.log("After : " + a.oops);

Remediation

Upgrade deep-extend to version 0.5.1 or higher.

References

Fixed in 5.2.0

npm Token Leak

medium severity

Detailed paths

  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4

Overview

This vulnerability could cause the unintentional leakage of bearer tokens. A design flaw in npm's registry allows an attacker to set up an HTTP server that could collect authentication information, and then use this authentication information to impersonate the users whose tokens they collected. The attacker could do anything the compromised users could do, including publishing new versions of packages.

Details

The primary npm registry has, since late 2014, used HTTP bearer tokens to authenticate requests from the npm command-line interface. Due to a design flaw in the CLI, these bearer tokens were sent with every request made by logged-in users, regardless of the destination of the request. (The bearers only should have been included for requests made against a registry or registries used for the current install.)

This flaw allows an attacker to set up an HTTP server that could collect authentication information. They could then use this information to impersonate the users whose tokens they collected. This impersonation would allow them to do anything the compromised users could do, including publishing new versions of packages.

With the fixes npm have released, the CLI will only send bearer tokens with requests made against a registry. npm’s CLI team believe that the fix won’t break any existing registry setups. However, it’s possible the change will be breaking in some cases, due to the large number of registry software suites used.

Remediation

  1. Upgrade npm to ">= 3.8.3 || >= 2.15.1"
  2. Invalidate your current npm bearer tokens

References

Regular Expression Denial of Service (ReDoS)

medium severity

Detailed paths

  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > semver@2.0.11
  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npmconf@0.1.16 > semver@2.3.2
  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > read-installed@0.2.5 > semver@2.3.2
  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > read-package-json@1.1.9 > normalize-package-data@0.2.13 > semver@2.3.2
  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > npmconf@0.1.16 > semver@2.3.2
  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > semver@2.1.0
  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > node-gyp@0.10.10 > semver@2.1.0
  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > npm-registry-client@0.2.31 > semver@2.3.2
  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > init-package-json@0.0.10 > semver@2.3.2

Overview

npm is a package manager for javascript.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). The semver module uses regular expressions when parsing a version string. For a carefully crafted input, the time it takes to process these regular expressions is not linear to the length of the input. Since the semver module did not enforce a limit on the version string length, an attacker could provide a long string that would take up a large amount of resources, potentially taking a server down. This issue therefore enables a potential Denial of Service attack. This is a slightly differnt variant of a typical Regular Expression Denial of Service (ReDoS) vulnerability.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Update to a version 4.3.2 or greater. From the issue description [2]: "Package version can no longer be more than 256 characters long. This prevents a situation in which parsing the version number can use exponentially more time and memory to parse, leading to a potential denial of service."

References

Denial of Service (Event Loop Blocking)

medium severity

Detailed paths

  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > request@2.21.0 > qs@0.6.6

Overview

qs is a querystring parser that supports nesting and arrays, with a depth limit.

Affected versions of this package are vulnerable to Denial of Service (DoS). When parsing a string representing a deeply nested object, qs will block the event loop for long periods of time. Such a delay may hold up the server's resources, keeping it from processing other requests in the meantime, thus enabling a Denial-of-Service attack.

Remediation

Update qs to version 1.0.0 or higher. In these versions, qs enforces a max object depth (along with other limits), limiting the event loop length and thus preventing such an attack.

References

Unsigned Request Headers

medium severity

Detailed paths

  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > request@2.21.0 > http-signature@0.9.11

Overview

http-signature is a Reference implementation of Joyent's HTTP Signature scheme. Affected versions of the package are vulnerable to header forgery, due to the header names not being signed. An attacker could switch the header list order and header value order ending up wit the same signature for two separate requests.

Remediation

Upgrade http-signature to version 0.10.0 or higher.

References

Uninitialized Memory Exposure

high severity

Detailed paths

  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npmconf@0.1.16
  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > npmconf@0.1.16

Overview

Affected versions of npmconf are vulnerable to Uninitialized Memory Exposure. It allocates and writes to disk uninitialized memory content when a typed number is passed as input.

Details

The Buffer class on Node.js is a mutable array of binary data, and can be initialized with a string, array or number.

const buf1 = new Buffer([1,2,3]);
// creates a buffer containing [01, 02, 03]
const buf2 = new Buffer('test');
// creates a buffer containing ASCII bytes [74, 65, 73, 74]
const buf3 = new Buffer(10);
// creates a buffer of length 10

The first two variants simply create a binary representation of the value it received. The last one, however, pre-allocates a buffer of the specified size, making it a useful buffer, especially when reading data from a stream. When using the number constructor of Buffer, it will allocate the memory, but will not fill it with zeros. Instead, the allocated buffer will hold whatever was in memory at the time. If the buffer is not zeroed by using buf.fill(0), it may leak sensitive information like keys, source code, and system info.

Remediation

Upgrade npmconf to version 2.1.3. Note npmconf is deprecated and should not be used. Note This is vulnerable only for Node <=4

References

Denial of Service (Memory Exhaustion)

high severity

Detailed paths

  • Introduced through: cordova@5.1.1 > cordova-lib@5.1.1 > npm@1.3.4 > request@2.21.0 > qs@0.6.6

Overview

qs is a querystring parser that supports nesting and arrays, with a depth limit.

Affected versions of this package are vulnerable to Denial of Service (Dos) attacks. During parsing, the qs module may create a sparse area (an array where no elements are filled), and grow that array to the necessary size based on the indices used on it. An attacker can specify a high index value in a query string, thus making the server allocate a respectively big array. Truly large values can cause the server to run out of memory and cause it to crash - thus enabling a Denial-of-Service attack.

Remediation

Upgrade qs to version 1.0.0 or greater. In these versions, qs introduced a low limit on the index value, preventing such an attack

References

Fixed in 5.1.1

Regular Expression Denial of Service (DoS)

medium severity

Detailed paths

  • Introduced through: browserify@5.0.0 > umd@2.1.0 > uglify-js@2.4.24
  • Introduced through: browserify@5.0.0 > umd@2.1.0 > ruglify@1.0.0 > uglify-js@2.2.5
  • Introduced through: cordova@5.0.0 > cordova-lib@5.0.0 > cordova-js@3.9.0 > browserify@7.1.0 > browser-pack@3.2.0 > umd@2.1.0 > uglify-js@2.4.24
  • Introduced through: cordova@5.0.0 > cordova-lib@5.0.0 > cordova-js@3.9.0 > browserify@7.1.0 > umd@2.1.0 > uglify-js@2.4.24
  • Introduced through: cordova@5.0.0 > cordova-lib@5.0.0 > cordova-js@3.9.0 > browserify@7.1.0 > browser-pack@3.2.0 > umd@2.1.0 > ruglify@1.0.0 > uglify-js@2.2.5
  • Introduced through: cordova@5.0.0 > cordova-lib@5.0.0 > cordova-js@3.9.0 > browserify@7.1.0 > umd@2.1.0 > ruglify@1.0.0 > uglify-js@2.2.5

Overview

The parse() function in the uglify-js package prior to version 2.6.0 is vulnerable to regular expression denial of service (ReDoS) attacks when long inputs of certain patterns are processed.

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade to version 2.6.0 or greater. If a direct dependency update is not possible, use snyk wizard to patch this vulnerability.

References

Improper minification of non-boolean comparisons

high severity

Detailed paths

  • Introduced through: browserify@5.0.0 > umd@2.1.0 > ruglify@1.0.0 > uglify-js@2.2.5
  • Introduced through: cordova@5.0.0 > cordova-lib@5.0.0 > cordova-js@3.9.0 > browserify@7.1.0 > browser-pack@3.2.0 > umd@2.1.0 > ruglify@1.0.0 > uglify-js@2.2.5
  • Introduced through: cordova@5.0.0 > cordova-lib@5.0.0 > cordova-js@3.9.0 > browserify@7.1.0 > umd@2.1.0 > ruglify@1.0.0 > uglify-js@2.2.5

Overview

uglify-js is a JavaScript parser, minifier, compressor and beautifier toolkit.

Tom MacWright discovered that UglifyJS versions 2.4.23 and earlier are affected by a vulnerability which allows a specially crafted Javascript file to have altered functionality after minification. This bug was demonstrated by Yan to allow potentially malicious code to be hidden within secure code, activated by minification.

Details

In Boolean algebra, DeMorgan's laws describe the relationships between conjunctions (&&), disjunctions (||) and negations (!). In Javascript form, they state that:

 !(a && b) === (!a) || (!b)
 !(a || b) === (!a) && (!b)

The law does not hold true when one of the values is not a boolean however.

Vulnerable versions of UglifyJS do not account for this restriction, and erroneously apply the laws to a statement if it can be reduced in length by it.

Consider this authentication function:

function isTokenValid(user) {
    var timeLeft =
        !!config && // config object exists
        !!user.token && // user object has a token
        !user.token.invalidated && // token is not explicitly invalidated
        !config.uninitialized && // config is initialized
        !config.ignoreTimestamps && // don't ignore timestamps
        getTimeLeft(user.token.expiry); // > 0 if expiration is in the future

    // The token must not be expired
    return timeLeft > 0;
}

function getTimeLeft(expiry) {
  return expiry - getSystemTime();
}

When minified with a vulnerable version of UglifyJS, it will produce the following insecure output, where a token will never expire:

( Formatted for readability )

function isTokenValid(user) {
    var timeLeft = !(                       // negation
        !config                             // config object does not exist
        || !user.token                      // user object does not have a token
        || user.token.invalidated           // token is explicitly invalidated
        || config.uninitialized             // config isn't initialized
        || config.ignoreTimestamps          // ignore timestamps
        || !getTimeLeft(user.token.expiry)  // > 0 if expiration is in the future
    );
    return timeLeft > 0
}

function getTimeLeft(expiry) {
    return expiry - getSystemTime()
}

Remediation

Upgrade UglifyJS to version 2.4.24 or higher.

References

Fixed in 4.2.0

Insecure Randomness

high severity

Detailed paths

  • Introduced through: cordova@4.1.3-nightly.2014.10.21 > cordova-lib@4.1.3-nightly.2014.10.21 > cordova-js@3.7.2 > browserify@3.46.0 > crypto-browserify@1.0.9

Overview

crypto-browserify is implementation of crypto for the browser.

Affected versions of the package are vulnerable to Insecure Randomness due to using the cryptographically insecure Math.random(). This function can produce predictable values and should not be used in security-sensitive context.

Details

Computers are deterministic machines, and as such are unable to produce true randomness. Pseudo-Random Number Generators (PRNGs) approximate randomness algorithmically, starting with a seed from which subsequent values are calculated.

There are two types of PRNGs: statistical and cryptographic. Statistical PRNGs provide useful statistical properties, but their output is highly predictable and forms an easy to reproduce numeric stream that is unsuitable for use in cases where security depends on generated values being unpredictable. Cryptographic PRNGs address this problem by generating output that is more difficult to predict. For a value to be cryptographically secure, it must be impossible or highly improbable for an attacker to distinguish between it and a truly random value. In general, if a PRNG algorithm is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts.

You can read more about node's insecure Math.random() in Mike Malone's post.

Remediation

Upgrade crypto-browserify to version 2.1.11 or higher.

References

Fixed in 3.3.1-0.3.0

Regular Expression Denial of Service (ReDoS)

high severity

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > express@3.0.0 > fresh@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > express@3.0.0 > connect@2.6.0 > fresh@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > express@3.0.0 > connect@2.6.0 > send@0.0.4 > fresh@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > express@3.0.0 > send@0.1.0 > fresh@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > send@0.1.0 > fresh@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > connect@2.7.2 > send@0.1.0 > fresh@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > fresh@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > connect@2.7.2 > fresh@0.1.0

Overview

fresh is HTTP response freshness testing.

Affected versions of this package are vulnerable to Regular expression Denial of Service (ReDoS) attacks. A Regular Expression (/ *, */) was used for parsing HTTP headers and take about 2 seconds matching time for 50k characters.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade fresh to version 0.5.2 or higher.

References

Regular Expression Denial of Service (ReDoS)

high severity
  • Vulnerable module: tough-cookie
  • Introduced through: npm@1.3.26

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > npm@1.3.26 > request@2.30.0 > tough-cookie@0.9.15

Overview

tough-cookie Hawk is an HTTP authentication scheme using a message authentication code (MAC) algorithm to provide partial HTTP request cryptographic verification.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks. An attacker can provide a cookie, which nearly matches the pattern being matched. This will cause the regular expression matching to take a long time, all the while occupying the event loop and preventing it from processing other requests and making the server unavailable (a Denial of Service attack).

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade tough-cookie to at version 2.3.0 or greater.

References

Arbitrary Command Injection

high severity
  • Vulnerable module: open
  • Introduced through: open@0.0.3

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > open@0.0.3

Overview

open Open a file or url in the user's preferred application.

Affected versions of this package are vulnerable to Arbitrary Command Injection. Urls are not properly escaped before concatenating them into the command that is opened using exec().

Remediation

There is no fix version for open.

References

Cross-site Scripting (XSS)

medium severity

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > express@3.0.0
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0

Overview

express is a minimalist web framework.

Affected versions of this package do not enforce the user's browser to set a specific charset in the content-type header while displaying 400 level response messages. This could be used by remote attackers to perform a cross-site scripting attack, by using non-standard encodings like UTF-7.

Details

Cross-Site Scripting (XSS) attacks occur when an attacker tricks a user’s browser to execute malicious JavaScript code in the context of a victim’s domain. Such scripts can steal the user’s session cookies for the domain, scrape or modify its content, and perform or modify actions on the user’s behalf, actions typically blocked by the browser’s Same Origin Policy.

These attacks are possible by escaping the context of the web application and injecting malicious scripts in an otherwise trusted website. These scripts can introduce additional attributes (say, a "new" option in a dropdown list or a new link to a malicious site) and can potentially execute code on the clients side, unbeknown to the victim. This occurs when characters like \< > \" \' are not escaped properly.

There are a few types of XSS:

  • Persistent XSS is an attack in which the malicious code persists into the web app’s database.
  • Reflected XSS is an which the website echoes back a portion of the request. The attacker needs to trick the user into clicking a malicious link (for instance through a phishing email or malicious JS on another page), which triggers the XSS attack.
  • DOM-based XSS is an that occurs purely in the browser when client-side JavaScript echoes back a portion of the URL onto the page. DOM-Based XSS is notoriously hard to detect, as the server never gets a chance to see the attack taking place.

Recommendations

Update express to 3.11.0, 4.5.0 or higher.

References

Regular Expression Denial of Service (ReDoS)

low severity

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > moment@1.7.2

Overview

moment is a lightweight JavaScript date library for parsing, validating, manipulating, and formatting dates.

Affected versions of this package are vulnerable to Regular expression Denial of Service (ReDoS) attacks. It used a regular expression (/[0-9]*['a-z\u00A0-\u05FF\u0700-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+|[\u0600-\u06FF\/]+(\s*?[\u0600-\u06FF]+){1,2}/i) in order to parse dates specified as strings. This can cause a very low impact of about 2 seconds matching time for data 50k characters long.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade moment to version 2.19.3 or higher.

References

Non-Constant Time String Comparison

medium severity

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > cookie-signature@0.0.1
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > connect@2.7.2 > cookie-signature@0.0.1

Overview

'cookie-signature' is a library for signing cookies.

Versions before 1.0.4 of the library use the built-in string comparison mechanism, ===, and not a time constant string comparison. As a result, the comparison will fail faster when the first characters in the token are incorrect. An attacker can use this difference to perform a timing attack, essentially allowing them to guess the secret one character at a time.

You can read more about timing attacks in Node.js on the Snyk blog: https://snyk.io/blog/node-js-timing-attack-ccc-ctf/

Remediation

Upgrade to 1.0.4 or greater.

References

Cross-site Scripting (XSS)

medium severity

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > express@3.0.0 > connect@2.6.0
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > connect@2.7.2

Overview

Connect is a stack of middleware that is executed in order in each request.

The "methodOverride" middleware allows the http post to override the method of the request with the value of the _method post key or with the header "x-http-method-override".

Because the user post input was not checked, req.method could contain any kind of value. Because the req.method did not match any common method VERB, connect answered with a 404 page containing the "Cannot [method] [url]" content. The method was not properly encoded for output in the browser.

Source: Node Security Project

Example

~ curl "localhost:3000" -d "_method=<script src=http://nodesecurity.io/xss.js></script>"
Cannot <SCRIPT SRC=HTTP://NODESECURITY.IO/XSS.JS></SCRIPT> /

Mitigation factors

Update to the newest version of Connect or disable methodOverride. It is not possible to avoid the vulnerability if you have enabled this middleware in the top of your stack.

History

Details

Cross-Site Scripting (XSS) attacks occur when an attacker tricks a user’s browser to execute malicious JavaScript code in the context of a victim’s domain. Such scripts can steal the user’s session cookies for the domain, scrape or modify its content, and perform or modify actions on the user’s behalf, actions typically blocked by the browser’s Same Origin Policy.

These attacks are possible by escaping the context of the web application and injecting malicious scripts in an otherwise trusted website. These scripts can introduce additional attributes (say, a "new" option in a dropdown list or a new link to a malicious site) and can potentially execute code on the clients side, unbeknown to the victim. This occurs when characters like \< > \" \' are not escaped properly.

There are a few types of XSS:

  • Persistent XSS is an attack in which the malicious code persists into the web app’s database.
  • Reflected XSS is an which the website echoes back a portion of the request. The attacker needs to trick the user into clicking a malicious link (for instance through a phishing email or malicious JS on another page), which triggers the XSS attack.
  • DOM-based XSS is an that occurs purely in the browser when client-side JavaScript echoes back a portion of the URL onto the page. DOM-Based XSS is notoriously hard to detect, as the server never gets a chance to see the attack taking place.

Regular Expression Denial of Service (ReDoS)

medium severity
  • Vulnerable module: tough-cookie
  • Introduced through: npm@1.3.26

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > npm@1.3.26 > request@2.30.0 > tough-cookie@0.9.15

Overview

tough-cookie is RFC6265 Cookies and Cookie Jar for node.js.

Affected versions of this package are vulnerable to Regular expression Denial of Service (ReDoS) attacks. An attacker may pass a specially crafted cookie, causing the server to hang.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade to version 2.3.3 or newer.

References

Directory Traversal

medium severity

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > express@3.0.0 > connect@2.6.0 > send@0.0.4
  • Introduced through: cordova@3.3.1-0.1.2 > express@3.0.0 > send@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > send@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > connect@2.7.2 > send@0.1.0

Overview

send is a library for streaming files from the file system.

Affected versions of this package are vulnerable to Directory-Traversal attacks due to insecure comparison. When relying on the root option to restrict file access a malicious user may escape out of the restricted directory and access files in a similarly named directory. For example, a path like /my-secret is consedered fine for the root /my.

Details

A Directory traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating variables that reference files with “dot-dot-slash (../)” sequences and its variations or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system including application source code, configuration and other critical system files.

Directory traversal vulnerabilities can be generally divided into two types:

  • Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.

st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.

If an attacker requests the following URL from our server, it will in turn, leak the sensitive private key of the root user.

curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa

Note %2e is the URL encoded version of . (dot).

  • Writing arbitrary files: Allows the attacker to create or replace existing files.

This can be achieved using a specially crafted zip archive, that holds path traversal filenames. So when the filename gets concatenated to the target extraction folder, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicous file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:

2018-04-15 22:04:29 .....           19           19  good.txt
2018-04-15 22:04:42 .....           20           20  ../../../../../../root/.ssh/authorized_keys

Remediation

Upgrade to a version greater than or equal to 0.8.4.

References

Insecure use of /tmp folder

low severity

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > jshint@1.1.0 > cli@0.4.5

Overview

cli is an npm package used for rapidly building command line apps.

When used in daemon mode, the library makes insecure use of two files in the /tmp/ folder: /tmp/<app-name>.pid and /tmp/<app-name>.log. These allow an attacker to overwrite files they typically cannot access, but that are accessible by the user running the CLI-using app. This is possible since the /tmp/ folder is (typically) writeable to all system users, and because the names of the files in question are easily predicted by an attacker.

Note that while this is a real vulnerability, it relies on functionality (daemon mode) which is only supported in very old Node versions (0.8 or older), and so is unlikely to be used by most cli users. To avoid any doubt, the fixed version (1.0.0) removes support for this feature entirely.

Details

For example, assume user victim occasionally runs a CLI tool called cli-tool, which uses the cli package. If an attacker gains write access to the /tmp/ folder of that machine (but not the higher permissions victim has), they can create the symbolic link /tmp/cli-tool.pid -> /home/victim/important-file. When victim runs cli-tool, the important-file in victim's root directory will be nullified. If the CLI tool is run as root, the same can be done to nullify /etc/passwd and make the system unbootable.

Note that popular CLI tools have no reason to mask their names, and so attackers can easily guess a long list of tools victims may run by checking the cli package dependents.

Remediation

Upgrade cli to version 1.0.0 or greater, which disables the affected feature.

From the fix release notes:

This feature relies on a beta release (e.g. version 0.5.1) of a Node.js
module on npm--one that was superseded by a stable (e.g. version 1.0)
release published three years ago [2]. Due to a build-time dependency on
the long-since deprecated `node-waf` tool, the module at that version
can only be built for Node.js versions 0.8 and below.

Given this, actual usage of this feature is likely very limited. Remove
it completely so the integrity of this module's core functionality can
be verified.

References

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=809252 [2] https://github.com/node-js-libs/cli/commit/fd6bc4d2a901aabe0bb6067fbcc14a4fe3faa8b9

Root Path Disclosure

medium severity

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > express@3.0.0 > connect@2.6.0 > send@0.0.4
  • Introduced through: cordova@3.3.1-0.1.2 > express@3.0.0 > send@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > send@0.1.0
  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > express@3.1.0 > connect@2.7.2 > send@0.1.0

Overview

Send is a library for streaming files from the file system as an http response. It supports partial responses (Ranges), conditional-GET negotiation, high test coverage, and granular events which may be leveraged to take appropriate actions in your application or framework.

Affected versions of this package are vulnerable to a Root Path Disclosure.

Remediation

Upgrade send to version 0.11.1 or higher. If a direct dependency update is not possible, use snyk wizard to patch this vulnerability.

References

Regular Expression Denial of Service (ReDoS)

medium severity

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > moment@1.7.2

Overview

moment is a lightweight JavaScript date library for parsing, validating, manipulating, and formatting dates.

Affected versions of the package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks for any locale that has separate format and standalone options and format input can be controlled by the user.

An attacker can provide a specially crafted input to the format function, which nearly matches the pattern being matched. This will cause the regular expression matching to take a long time, all the while occupying the event loop and preventing it from processing other requests and making the server unavailable (a Denial of Service attack).

Disclosure Timeline

  • October 19th, 2016 - Reported the issue to package owner.
  • October 19th, 2016 - Issue acknowledged by package owner.
  • October 24th, 2016 - Issue fixed and version 2.15.2 released.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

References

Regular Expression Denial of Service (ReDoS)

low severity

Detailed paths

  • Introduced through: cordova@3.3.1-0.1.2 > ripple-emulator@0.9.18 > moment@1.7.2

Overview

moment is a lightweight JavaScript date library for parsing, validating, manipulating, and formatting dates.

An attacker can provide a long value to the duration function, which nearly matches the pattern being matched. This will cause the regular expression matching to take a long time, all the while occupying the event loop and preventing it from processing other requests and making the server unavailable (a Denial of Service attack).

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  1. CCC
  2. CC+C
  3. C+CC
  4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

String Number of C's Number of steps
ACCCX 3 38
ACCCCX 4 71
ACCCCCX 5 136
ACCCCCCCCCCCCCCX 14 65,553

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade moment to version 2.11.2 or greater.

References

Fixed in 2.3.0

Arbitrary File Write via Archive Extraction (Zip Slip)

high severity

Detailed paths

  • Introduced through: cordova@2.2.0 > adm-zip@0.1.8

Overview

adm-zip is a Javascript implementation of zip for NodeJS with support for electron original-fs.

Affected versions of the package are vulnerable to Arbitrary File Write via Archive Extraction (AKA "Zip Slip").

It can be exploited using a specially crafted zip archive, that holds path traversal filenames. When exploited, a filename in a malicious archive is concatenated to the target extraction directory, which results in the final path ending up outside of the target folder. For instance, a zip may hold a file with a ../../file.exe location and thus break out of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicous file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:

+2018-04-15 22:04:29 .....           19           19  good.txt
+2018-04-15 22:04:42 .....           20           20  ../../../../../../root/.ssh/authorized_keys

Remediation

Upgrade adm-zip to version 0.4.11 or higher.

References