Public Date:
518182: CVE-2009-2855 squid: DoS (100% CPU use) while processing certain external ACL helper HTTP headers

The MITRE CVE dictionary describes this issue as:

The strListGetItem function in src/HttpHeaderTools.c in Squid 2.7 allows remote attackers to cause a denial of service via a crafted auth header with certain comma delimiters that trigger an infinite loop of calls to the strcspn function.

Find out more about CVE-2009-2855 from the MITRE CVE dictionary dictionary and NIST NVD.


This issue did not affect the versions of the squid packages, as shipped with Red Hat Enterprise Linux 3 and 4.

The issue was addressed in the squid packages as shipped with Red Hat Enterprise Linux 5 via:

CVSS v2 metrics

Base Score 2.9
Base Metrics AV:A/AC:M/Au:N/C:N/I:N/A:P
Access Vector Adjacent Network
Access Complexity Medium
Authentication None
Confidentiality Impact None
Integrity Impact None
Availability Impact Partial

Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).

Red Hat Security Errata

Platform Errata Release Date
Red Hat Enterprise Linux 5 (squid) RHSA-2010:0221 2010-03-29


Last Modified

CVE description copyright © 2017, The MITRE Corporation