14 DAY TRIAL // On June 20, Canonical published in a security notice details about an HAProxy vulnerability for its Ubuntu 13.04, Ubuntu 12.10, and Ubuntu 12.04 LTS operating systems.
According to Canonical, HAProxy could have been made to crash if it received specially crafted network traffic.
It was discovered that the HAProxy incorrectly parsed certain HTTP headers. A remote attacker could use this issue to cause HAProxy to stop responding, resulting in a denial of service.
For a more detailed description of the security problems, you can visit Canonical's security notification.
The security flaws can be fixed if you upgrade your system(s) to the latest haproxy package, specific to each operating system. To apply the update, run the Update Manager application.
In general, a standard system update will make all the necessary changes. A system restart won't be necessary to implement the changes.