Rsyslog could be made to crash if it processed a specially crafted log message.
Peter Eisentraut discovered that Rsyslog would not properly perform input validation when configured to use imfile. If an attacker were able to craft messages in a file that Rsyslog monitored, an attacker could cause a denial of service. The imfile module is disabled by default in Ubuntu.
23 January 2012
A security issue affects these releases of Ubuntu and its derivatives:
Rsyslog could be made to crash if it processed a specially crafted log message.
Peter Eisentraut discovered that Rsyslog would not properly perform input validation when configured to use imfile. If an attacker were able to craft messages in a file that Rsyslog monitored, an attacker could cause a denial of service. The imfile module is disabled by default in Ubuntu.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.