Fail2ban: Denial of service

Background

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

Description

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

Impact

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.

Workaround

There is no known workaround at this time.

Resolution

All Fail2ban users should upgrade to the latest version:

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