Find, fix and prevent vulnerabilities in your code.

Overview

Twisted is an event-based network programming and multi-protocol integration framework.

Affected versions of this package are vulnerable to Arbitrary Command Injection via improper input sanitization in the file upload process. An attacker can execute arbitrary commands on the target system by sending a specially crafted HTTP PUT request to upload a malicious file and subsequently triggering its execution. This can result in remote code execution and potential privilege escalation depending on the web server's permissions.

Remediation

There is no fixed version for Twisted.

References

• Medium Blog

Overview

Twisted is an event-based network programming and multi-protocol integration framework.

Affected versions of this package are vulnerable to HTTP Response Smuggling. When sending multiple HTTP/1.1 requests in one TCP segment, twisted.web does not guarantee the response order. An attacker in control of an endpoint can manipulate a different user's second response to a pipelined chunked request by delaying the response to their own request. Information disclosure across sessions may also be possible for reverse proxy servers using pooled connections.

Workaround

This vulnerability can be avoided by enforcing HTTP/2, as it is only vulnerable for HTTP/1.x traffic.

Remediation

Upgrade Twisted to version 24.7.0rc1 or higher.

References

• GitHub Commit
• GitHub Issue

Overview

Affected versions of this package are vulnerable to Infinite loop where an attacker can cause the application to stop responding by initiating a loop through functions affecting the Path module, such as joinpath, the overloaded division operator, and iterdir.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade zipp to version 3.19.1 or higher.

References

• GitHub Commit
• GitHub Issue
• GitHub PR

Overview

Affected versions of this package are vulnerable to Directory Traversal through the ‎PackageIndex._download_url method. Due to insufficient sanitization of special characters, an attacker can write files to arbitrary locations on the filesystem with the permissions of the process running the Python code. In certain scenarios, an attacker could potentially escalate to remote code execution by leveraging malicious URLs present in a package index.

PoC

python poc.py
# Payload file: http://localhost:8000/%2fhome%2fuser%2f.ssh%2fauthorized_keys
# Written to: /home/user/.ssh/authorized_keys

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 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 type of vulnerability is also known as Zip-Slip.

One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, 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 malicious 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 setuptools to version 78.1.1 or higher.

References

• GitHub Commit
• GitHub Issue
• Vulnerable Code

Overview

Scrapy is a high-level web crawling and web scraping framework, used to crawl websites and extract structured data from their pages.

Affected versions of this package are vulnerable to Files or Directories Accessible to External Parties via the DOWNLOAD_HANDLERS setting. An attacker can redirect traffic to unintended protocols such as file:// or s3://, potentially accessing sensitive data or credentials by manipulating the start URLs of a spider and observing the output.

Notes:

1. HTTP redirects should only work between URLs that use the http:// or https:// schemes.

2. A malicious actor, given write access to the start requests of a spider and read access to the spider output, could exploit this vulnerability to:

a) Redirect to any local file using the file:// scheme to read its contents.

b) Redirect to an ftp:// URL of a malicious FTP server to obtain the FTP username and password configured in the spider or project.

c) Redirect to any s3:// URL to read its content using the S3 credentials configured in the spider or project.

3. A spider that always outputs the entire contents of a response would be completely vulnerable.

4. A spider that extracted only fragments from the response could significantly limit vulnerable data.

Remediation

Upgrade Scrapy to version 2.11.2 or higher.

References

• GitHub Commit
• GitHub Issue

Overview

Affected versions of this package are vulnerable to Improper Certificate Validation through the NameChain DNS verification logic in src/rust/cryptography-x509-verification. An attacker can make a peer name, such as bar.example.com, validate against a wildcard leaf certificate like *.example.com even when an issuing certificate in the chain excludes that DNS subtree, causing improper certificate acceptance.

Notes

• The flaw affects X.509 path validation when DNS name constraints are present, and the leaf certificate uses a wildcard DNS SAN.
• The maintainers note that ordinary X.509 topologies, including those used by the Web PKI, are not affected, and exploitation requires an uncommon certificate hierarchy.

Remediation

Upgrade cryptography to version 46.0.6 or higher.

References

• GitHub Commit
• Maintainer's Advisory

Overview

Affected versions of this package are vulnerable to Not Failing Securely ('Failing Open') via the set_tlsext_servername_callback function. An attacker can bypass security-sensitive checks by causing an unhandled exception in the callback, which results in the connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it.

Remediation

Upgrade pyopenssl to version 26.0.0 or higher.

References

• GitHub ChangeLog
• GitHub Commit

Overview

Affected versions of this package are vulnerable to Incorrect Behavior Order in the DNS pre-processing pipeline, which allows an off-path attacker who can spoof the source IP address of a malformed DNS response packet to cause denial of service. The UDP processing functions in query.py and asyncquery.py accept the first-arriving packet before closing the receiving socket, allowing the attacker to make the remote nameserver appear unavailable for the target resolver and clients.

Remediation

Upgrade dnspython to version 2.6.1 or higher.

References

• GitHub Commit
• GitHub Issue
• Tudoor Paper

Overview

Scrapy is a high-level web crawling and web scraping framework, used to crawl websites and extract structured data from their pages.

Affected versions of this package are vulnerable to Exposure of Sensitive Information to an Unauthorized Actor due to improper handling of HTTP headers during cross-origin redirects. An attacker can intercept the Authorization header and potentially access sensitive information by exploiting this misconfiguration in redirect scenarios where the domain remains the same but the scheme or port changes.

Note: In the context of a man-in-the-middle attack, this could be used to get access to the value of that Authorization header.

Remediation

Upgrade Scrapy to version 2.11.2 or higher.

References

• GitHub Commit

Overview

Scrapy is a high-level web crawling and web scraping framework, used to crawl websites and extract structured data from their pages.

Affected versions of this package are vulnerable to Information Exposure in which a spider could leak cookie headers when being forwarded to a third party, potentially attacker-controlled website.

Remediation

Upgrade Scrapy to version 2.6.0 or higher.

References

• GitHub Commit

Overview

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via crafted HTML package or custom PackageIndex page.

Note:

Only a small portion of the user base is impacted by this flaw. Setuptools maintainers pointed out that package_index is deprecated (not formally, but “in spirit”) and the vulnerability isn't reachable through standard, recommended workflows.

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.

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 setuptools to version 65.5.1 or higher.

References

• GitHub Commit
• GitHub Issue
• GitHub Release
• Pyup Blog
• Vulnerable Code

Overview

Scrapy is a high-level web crawling and web scraping framework, used to crawl websites and extract structured data from their pages.

Affected versions of this package are vulnerable to Information Exposure. If you use HttpAuthMiddleware (i.e. the http_user and http_pass spider attributes) for HTTP authentication, all requests will expose your credentials to the request target. This includes requests generated by Scrapy components, such as robots.txt requests sent by Scrapy when the ROBOTSTXT_OBEY setting is set to True, or as requests reached through redirects.

Remediation

Upgrade Scrapy to version 2.5.1, 1.8.1 or higher.

References

• GitHub Commit

Overview

Scrapy is a high-level web crawling and web scraping framework, used to crawl websites and extract structured data from their pages.

Affected versions of this package are vulnerable to Credential Exposure via the process_request() function in downloadermiddlewares/httpproxy.py. A proxy can leak credentials to another proxy if third-party downloader middlewares leave Proxy-Authentication headers unchanged when updating proxy metadata for a new request.

NOTE: To fully mitigate the effects of vulnerability, replacing or upgrading the third-party downloader middleware might be necessary after upgrading.

Remediation

Upgrade Scrapy to version 1.8.3, 2.6.2 or higher.

References

• GitHub Commit

Overview

Twisted is an event-based network programming and multi-protocol integration framework.

Affected versions of this package are vulnerable to HTTP Response Smuggling. When sending multiple HTTP/1.1 requests in one TCP segment, twisted.web does not guarantee the response order. An attacker in control of an endpoint can manipulate a different user's second response to a pipelined chunked request by delaying the response to their own request.

Workaround

This vulnerability can be avoided by enforcing HTTP/2, as it is only vulnerable for HTTP/1.x traffic.

Remediation

Upgrade Twisted to version 23.10.0rc1 or higher.

References

• GitHub Commit
• GitHub Issue
• GitHub Release

Overview

via S3FilesStore. Files are stored in memory before uploaded to s3, increasing memory usage if giant or many files are being uploaded at the same time.

References

• https://github.com/scrapy/scrapy/issues/482
• https://github.com/scrapy/scrapy/pull/2917

Overview

Twisted is an event-based network programming and multi-protocol integration framework.

Affected versions of this package are vulnerable to Cross-site Scripting (XSS) when the victim is using Firefox, due to an unescaped URL in the redirectTo() function. A site which is vulnerable to open redirects by other means can be can be made to execute scripts injected into a redirect URL.

PoC

http://127.0.0.1:9009?url=ws://example.com/"><script>alert(document.location)</script>

Details

Cross-site scripting (or XSS) is a code vulnerability that occurs when an attacker “injects” a malicious script into an otherwise trusted website. The injected script gets downloaded and executed by the end user’s browser when the user interacts with the compromised website.

This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser’s Same Origin Policy.

Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.

Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as &lt; and > can be coded as &gt; in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they’ve been correctly escaped in the application code and in this way the attempted attack is diverted.

The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.

Types of attacks

There are a few methods by which XSS can be manipulated:

Affected environments

The following environments are susceptible to an XSS attack:

• Web servers
• Application servers
• Web application environments

How to prevent

This section describes the top best practices designed to specifically protect your code:

• Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
• Convert special characters such as ?, &, /, <, > and spaces to their respective HTML or URL encoded equivalents.
• Give users the option to disable client-side scripts.
• Redirect invalid requests.
• Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
• Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
• Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.

Remediation

Upgrade Twisted to version 24.7.0rc1 or higher.

References

• GitHub Commit
• GitHub Issue
• Nuclei Templates

Overview

Scrapy is a high-level web crawling and web scraping framework, used to crawl websites and extract structured data from their pages.

Affected versions of this package are vulnerable to URL Redirection to Untrusted Site ('Open Redirect') due to the improper handling of scheme-specific proxy settings during HTTP redirects. An attacker can potentially intercept sensitive information by exploiting the failure to switch proxies when redirected from HTTP to HTTPS URLs or vice versa.

Remediation

Upgrade Scrapy to version 2.11.2 or higher.

References

• GitHub Commit
• GitHub Issue