Critical WEBrick Vulnerability in ruby-webrick Package: Potential HTTP Request Smuggling Attack
Summary
USN-7709-1: ruby-webrick vulnerability. Affects ruby-webrick versions < 1.7.0-3ubuntu0.2. Fixed in 1.7.0-3ubuntu0.2. How to fix ↓
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Background
The ruby-webrick package is a Ruby library that provides an HTTP server toolkit. It is widely used for serving web applications and handling HTTP requests. WEBrick is known for its simplicity and ease of use, making it a popular choice for developers. However, it has been found to have a vulnerability that could allow attackers to exploit HTTP header parsing issues, particularly when deployed behind an HTTP proxy.
Vulnerability Detail
It was discovered that WEBrick incorrectly parsed HTTP headers. In configurations where WEBrick is placed behind an HTTP proxy, a remote attacker could possibly use this issue to perform an HTTP Request Smuggling attack. This vulnerability, identified as CVE-2025-6442, could lead to unauthorized access, data leakage, or other malicious activities, compromising the integrity and security of the web application.
How To Fix
Minimum fixed version
1.7.0-3ubuntu0.2
This is the first release that contains the fix.
sudo apt-get install --only-upgrade ruby-webrickTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
If immediate patching is not possible, consider configuring your HTTP proxy to mitigate the risk of HTTP Request Smuggling attacks. This may involve adjusting proxy settings or implementing additional security measures to validate and sanitize incoming HTTP requests.
Conclusion
The ruby-webrick package has a critical vulnerability that could lead to HTTP Request Smuggling attacks. It is crucial to update to the patched versions as soon as possible to safeguard your applications. If immediate updates are not feasible, consider implementing workarounds to mitigate risks.
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FAQ
The vulnerability involves incorrect parsing of HTTP headers by WEBrick, which can lead to HTTP Request Smuggling attacks when placed behind an HTTP proxy.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in your software. By simply using a manifest file like package-lock.json, you can check for vulnerabilities in your application.
Exploiting this vulnerability could allow attackers to gain unauthorized access, leak sensitive data, or manipulate HTTP requests, compromising the security of your web application.
Yes, you can configure your HTTP proxy to validate and sanitize incoming requests to reduce the risk of HTTP Request Smuggling attacks.
Detailed information about this vulnerability can be found in the Ubuntu Security Notices, specifically USN-7709-1, which outlines the issue and its implications.
References
Related vulnerabilities
Recent vulnerabilities recorded for ruby-webrick.
