CVE-2023-50269 : Exploit Details and Defense Strategies

A denial of service vulnerability in HTTP request parsing in the Squid caching proxy software has been identified and assigned CVE-2023-50269 by GitHub_M.

Understanding CVE-2023-50269

This CVE pertains to a vulnerability in Squid that allows an attacker to exploit uncontrolled recursion, leading to a denial of service condition in the HTTP request parsing functionality.

What is CVE-2023-50269?

Squid, a popular web caching proxy, was found to be vulnerable to a denial of service attack due to a bug in versions 2.6 through 2.7.STABLE9, versions 3.1 through 5.9, and versions 6.0.1 through 6.5. The vulnerability arises from an issue in processing large X-Forwarded-For headers.

The Impact of CVE-2023-50269

This vulnerability could be exploited by a remote attacker to launch a denial of service attack by sending specially crafted HTTP requests, potentially disrupting the availability of the Squid caching proxy servers.

Technical Details of CVE-2023-50269

This section provides further technical details about the vulnerability in Squid software.

Vulnerability Description

The vulnerability in Squid arises from uncontrolled recursion, specifically when handling large X-Forwarded-For headers, leading to a denial of service condition during HTTP request parsing.

Affected Systems and Versions

Squid versions 2.6 through 2.7.STABLE9, versions 3.1 through 5.9, and versions 6.0.1 through 6.5 are affected by this vulnerability.

Exploitation Mechanism

Remote attackers can exploit this vulnerability by sending specially crafted HTTP requests with large X-Forwarded-For headers, triggering uncontrolled recursion and causing a denial of service condition.

Mitigation and Prevention

In response to CVE-2023-50269, users and administrators can take the following steps to mitigate the risk and prevent exploitation of this vulnerability.

Immediate Steps to Take

Update Squid software to version 6.6 or newer to address the uncontrolled recursion bug.
Implement filtering rules to limit the size of X-Forwarded-For headers and prevent oversized headers from being processed.

Long-Term Security Practices

Regularly update Squid software to the latest stable releases to ensure that known vulnerabilities are patched promptly.
Monitor network traffic for any anomalous patterns that may indicate exploitation attempts targeting this vulnerability.

Patching and Updates

Patch releases for addressing the CVE-2023-50269 vulnerability can be found in Squid's patch archives for the affected versions. It is essential to apply these patches promptly to secure the Squid caching proxy servers against potential attacks.