Denial of Service Vulnerability in Ruby Package: CVE-2018-8777
Summary
ALPINE-CVE-2018-8777: In Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1, an attacker can pass a large HTTP request with a crafted header to WEBrick server or a crafted body to WEBrick server... Affects ruby versions < 2.5.1-r0. Fixed in 2.5.1-r0. How to fix ↓
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Background
Ruby is a dynamic, open-source programming language with a focus on simplicity and productivity. It is widely used for web development, particularly with the Ruby on Rails framework. The Ruby package provides essential libraries and tools for developers to build applications. However, certain versions of Ruby are vulnerable to a denial of service attack due to improper handling of HTTP requests in the WEBrick server, which can lead to significant memory consumption.
Vulnerability Detail
The vulnerability, identified as CVE-2018-8777, affects Ruby versions prior to 2.5.1. An attacker can exploit this vulnerability by sending a large HTTP request with a crafted header or body to the WEBrick server. This can result in excessive memory usage, causing the server to become unresponsive and leading to a denial of service. The issue arises from the server's inability to properly manage memory allocation for large requests, making it susceptible to attacks that aim to exhaust server resources.
How To Fix
Minimum fixed version
2.5.1-r0
This is the first release that contains the fix.
sudo apk add --upgrade rubyTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
If immediate upgrading is not feasible, consider implementing rate limiting on the WEBrick server to mitigate the impact of potential denial of service attacks. Additionally, monitor server logs for unusual request patterns that may indicate an ongoing attack.
Conclusion
CVE-2018-8777 is a significant vulnerability in Ruby that can lead to denial of service attacks through improper handling of HTTP requests in the WEBrick server. It is crucial for users to update to the patched version to protect their applications from potential exploitation.
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FAQ
CVE-2018-8777 is a vulnerability in Ruby that allows attackers to exploit the WEBrick server, leading to denial of service through excessive memory consumption.
Ruby versions prior to 2.5.1 are affected by this vulnerability.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
Implement rate limiting on the WEBrick server and monitor server logs for unusual activity as a temporary workaround.
The CVSS score for CVE-2018-8777 is 7.5, indicating a high severity level.
References
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