14 DAY TRIAL // On December 9, in a security notice, Canonical published details about a GIMP vulnerability in its Ubuntu 13.10, Ubuntu 13.04, Ubuntu 12.10, and Ubuntu 12.04 LTS operating systems.
According to the company, GIMP could be made to crash or run programs as the user’s login, if it opened a specially crafted file.
It has been discovered that GIMP incorrectly handled malformed XWD files. If a user were tricked into opening a specially crafted XWD file, an attacker could cause GIMP to crash, or possibly run with the user's privileges.
For a more detailed description of the problems, you can see Canonical's security notification.
The security flaws can be fixed if you upgrade your system(s) to the latest gimp package. To apply the patch, run the Update Manager application.
In general, a standard system update will make all the necessary changes and a restart is required.