Gentoo Logo

Fail2ban: Denial of Service


1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200707-13 / fail2ban
Release Date July 28, 2007
Latest Revision January 09, 2008: 02
Impact normal
Exploitable remote
Package Vulnerable versions Unaffected versions Architecture(s)
net-analyzer/fail2ban < 0.8.0-r1 >= 0.8.0-r1 All supported architectures

Related bugreports: #181214


Fail2ban is vulnerable to a Denial of Service attack.

2.  Impact Information


Fail2ban is a tool for parsing log files and banning IP addresses which make too many password failures.


A vulnerability has been discovered in Fail2ban when parsing log files.


A remote attacker could send specially crafted SSH login banners to the vulnerable host, which would prevent any ssh connection to the host and result in a Denial of Service.

3.  Resolution Information


There is no known workaround at this time.


All Fail2ban users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=net-analyzer/fail2ban-0.8.0-r1"

4.  References


Page updated July 28, 2007

Summary: This is a Gentoo Linux Security Advisory

Security Team
Contact Address

Donate to support our development efforts.

Copyright 2001-2015 Gentoo Foundation, Inc. Questions, Comments? Contact us.