On November 29, Canonical published details about Perl vulnerabilities for its Ubuntu 12.10 and Ubuntu 12.10, Ubuntu 12.04 LTS, Ubuntu 11.10, Ubuntu 10.04 LTS, Ubuntu 8.04 LTS operating systems.
According to Canonical, Perl programs could have been made to crash or run programs if they received specially crafted network traffic or other input.
For example, it was discovered that the decode_xs function in the Encode module is vulnerable to a heap-based buffer overflow via a crafted Unicode string. An attacker could have used this overflow to cause a denial of service.
For a more detailed description of the security problems, you can visit Canonical's security notification.
Users can simply fix the security flaws by upgrading the operating systems to the latest Perl package, specific to each distribution.
A normal system update, executed with the Update Manager, will implement all the necessary changes. A complete system restart is not necessary.