Root privilege escalation via symlink following.
Denis Excoffier discovered that the PAM MOTD module in Ubuntu did not correctly handle path permissions when creating user file stamps. A local attacker could exploit this to gain root privilieges.
7 July 2010
A security issue affects these releases of Ubuntu and its derivatives:
Root privilege escalation via symlink following.
Denis Excoffier discovered that the PAM MOTD module in Ubuntu did not correctly handle path permissions when creating user file stamps. A local attacker could exploit this to gain root privilieges.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.