14 DAY TRIAL // On September 30, in a security notice, Canonical published details about a txt2man vulnerability in its Ubuntu 13.04, Ubuntu 12.10, and Ubuntu 12.04 LTS operating systems.
According to Canonical, txt2man could have been made to overwrite files.
It was discovered that txt2man contained leftover debugging code that incorrectly created a temporary file. A local attacker could have possibly used this issue to overwrite arbitrary files. In the default Ubuntu installation, this should be prevented by the Yama link restrictions.
For a more detailed description of the security problems, you can see Canonical's security notification.
The security flaws can be fixed if you upgrade your system(s) to the latest systemd-services packages, specific to each distribution. To apply the update, run the Update Manager application.
In general, a standard system update will make all the necessary changes. A system restart will not be necessary to implement them.