Ubuntu Update for Linux kernel vulnerabilities USN-636-1

Please Install the Updated Packages.

Sebastian Krahmer discovered that Postfix was not correctly handling mailbox ownership when dealing with Linux's implementation of hardlinking to symlinks. In certain mail spool configurations, a local attacker could exploit this to append data to arbitrary files as the root user. The default Ubuntu configuration was not vulnerable.

postfix vulnerability on Ubuntu 6.06 LTS , Ubuntu 7.04 , Ubuntu 7.10 , Ubuntu 8.04 LTS