Snort: Denial of Service

Security Team  Contact Address

Updated February 13, 2007

1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200702-03 / snort
Release Date February 13, 2007
Latest Revision February 13, 2007: 01
Impact normal
Exploitable remote
Package Vulnerable versions Unaffected versions Architecture(s)
net-analyzer/snort < 2.6.1.2 >= 2.6.1.2 All supported architectures

Related bugreports: #161632

Synopsis

Snort contains a vulnerability in the rule matching algorithm that could result in a Denial of Service.

2.  Impact Information

Background

Snort is a widely deployed intrusion detection program.

Description

Randy Smith, Christian Estan and Somesh Jha discovered that the rule matching algorithm of Snort can be exploited in a way known as a "backtracking attack" to perform numerous time-consuming operations.

Impact

A remote attacker could send specially crafted network packets, which would result in the cessation of the detections and the consumption of the CPU resources.

3.  Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All Snort users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=net-analyzer/snort-2.6.1.2"

4.  References