typings-core@2.2.0

Vulnerabilities

4 via 4 paths

Dependencies

99

Source

npm

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Severity
  • 2
  • 2
Status
  • 4
  • 0
  • 0

high severity

Uninitialized Memory Exposure

  • Vulnerable module: http-proxy-agent
  • Introduced through: popsicle-proxy-agent@3.0.0

Detailed paths

  • Introduced through: typings-core@2.2.0 popsicle-proxy-agent@3.0.0 http-proxy-agent@1.0.0

Overview

http-proxy-agent provides an http.Agent implementation that connects to a specified HTTP or HTTPS proxy server, and can be used with the built-in http module.

Affected versions of this package are vulnerable to Uninitialized Memory Exposure and Denial of Service (DoS) attacks due to passing unsanitized options to Buffer(arg).

Uninitialized memory Exposre PoC by ChALKer

// listen with: nc -l -p 8080

var url = require('url');
var https = require('https');
var HttpsProxyAgent = require('https-proxy-agent');

var proxy = {
  protocol: 'http:',
  host: "127.0.0.1",
  port: 8080
};

proxy.auth = 500; // a number as 'auth'
var opts = url.parse('https://example.com/');
var agent = new HttpsProxyAgent(proxy);
opts.agent = agent;
https.get(opts);

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 https-proxy-agent to version 2.1.0 or higher. Note This is vulnerable only for Node <=4

References

high severity

Uninitialized Memory Exposure

  • Vulnerable module: https-proxy-agent
  • Introduced through: popsicle-proxy-agent@3.0.0

Detailed paths

  • Introduced through: typings-core@2.2.0 popsicle-proxy-agent@3.0.0 https-proxy-agent@1.0.0

Overview

https-proxy-agent provides an http.Agent implementation that connects to a specified HTTP or HTTPS proxy server, and can be used with the built-in https module.

Affected versions of this package are vulnerable to Uninitialized Memory Exposure and Denial of Service (DoS) attacks due to passing unsanitized options to Buffer(arg).

Uninitialized memory Exposre PoC by ChALKer

// listen with: nc -l -p 8080

var url = require('url');
var https = require('https');
var HttpsProxyAgent = require('https-proxy-agent');

var proxy = {
  protocol: 'http:',
  host: "127.0.0.1",
  port: 8080
};

proxy.auth = 500; // a number as 'auth'
var opts = url.parse('https://example.com/');
var agent = new HttpsProxyAgent(proxy);
opts.agent = agent;
https.get(opts);

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 https-proxy-agent to version 2.2.0 or higher. Note This is vulnerable only for Node <=4

References

medium severity

Prototype Pollution

  • Vulnerable module: dot-prop
  • Introduced through: configstore@2.1.0

Detailed paths

  • Introduced through: typings-core@2.2.0 configstore@2.1.0 dot-prop@3.0.0
    Remediation: Upgrade to typings-core@2.3.0.

Overview

dot-prop is a package to get, set, or delete a property from a nested object using a dot path.

Affected versions of this package are vulnerable to Prototype Pollution. It is possible for a user to modify the prototype of a base object.

PoC by aaron_costello

var dotProp = require("dot-prop")
const object = {};
console.log("Before " + object.b); //Undefined
dotProp.set(object, '__proto__.b', true);
console.log("After " + {}.b); //true

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 dot-prop to version 4.2.1, 5.1.1 or higher.

References

medium severity

Man-in-the-Middle (MitM)

  • Vulnerable module: https-proxy-agent
  • Introduced through: popsicle-proxy-agent@3.0.0

Detailed paths

  • Introduced through: typings-core@2.2.0 popsicle-proxy-agent@3.0.0 https-proxy-agent@1.0.0

Overview

https-proxy-agent is a module that provides an http.Agent implementation that connects to a specified HTTP or HTTPS proxy server, and can be used with the built-in https module.

Affected versions of this package are vulnerable to Man-in-the-Middle (MitM). When targeting a HTTP proxy, https-proxy-agent opens a socket to the proxy, and sends the proxy server a CONNECT request. If the proxy server responds with something other than a HTTP response 200, https-proxy-agent incorrectly returns the socket without any TLS upgrade. This request data may contain basic auth credentials or other secrets, is sent over an unencrypted connection. A suitably positioned attacker could steal these secrets and impersonate the client.

PoC by Kris Adler

var url = require('url');
var https = require('https');
var HttpsProxyAgent = require('https-proxy-agent');

var proxyOpts = url.parse('http://127.0.0.1:80');
var opts = url.parse('https://www.google.com');
var agent = new HttpsProxyAgent(proxyOpts);
opts.agent = agent;
opts.auth = 'username:password';
https.get(opts);

Remediation

Upgrade https-proxy-agent to version 2.2.3 or higher.

References