search menu icon-carat-right cmu-wordmark

CERT Coordination Center

Squid remote denial-of-service vulnerability

Vulnerability Note VU#232881

Original Release Date: 2007-12-10 | Last Revised: 2008-01-18

Overview

The Squid Proxy server contains a vulnerability that may allow an attacker to create a denial-of-service condition that affects the Squid server and systems that rely on it.

Description

Squid Proxy Cache is a caching proxy that supports the HTTP, HTTPS, and FTP protocols. Squid can also be deployed as a reverse proxy.

From Squid Proxy Cache Security Update Advisory SQUID-2007:2
Due to incorrect bounds checking Squid is vulnerable to a denial of service check during some cache update reply processing.
This incorrect bounds checking occurs within the httpHeaderUpdate() function when processing cache update replies.

Impact

An attacker who can access the Squid proxy may be able to cause the proxy server to crash. If the Squid proxy is deployed as a reverse proxy, the web servers relying on the proxy may also be affected.

Solution

Update
The Squid team has released patches 11780 and 11211 to address this issue. Administrators who obtain Squid from their operating system vendor should see the systems affected portion of this document for a partial list of affected vendors.


Restrict access

Restricting access to the Squid proxy via access control lists or firewall rules may prevent this vulnerability from being exploited by remote attackers..

Vendor Information

232881
 

View all 43 vendors View less vendors


CVSS Metrics

Group Score Vector
Base
Temporal
Environmental

References

Acknowledgements

The Squid proxy team credits the Wikimedia Foundation for discovering this vulnerability. Adrian Chadd and Henrik Nordstrom are credited for authoring patches that address the issue.

This document was written by Ryan Giobbi.

Other Information

CVE IDs: CVE-2007-6239
Severity Metric: 7.51
Date Public: 2007-11-27
Date First Published: 2007-12-10
Date Last Updated: 2008-01-18 16:35 UTC
Document Revision: 12

Sponsored by CISA.