USN-695-1: shadow vulnerability

18 December 2008

shadow vulnerability

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 8.10
  • Ubuntu 8.04 LTS
  • Ubuntu 7.10
  • Ubuntu 6.06 LTS

Software Description

  • shadow


Paul Szabo discovered a race condition in login. While setting up tty permissions, login did not correctly handle symlinks. If a local attacker were able to gain control of the system utmp file, they could cause login to change the ownership and permissions on arbitrary files, leading to a root privilege escalation.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 8.10
login - 1:4.1.1-1ubuntu1.2
Ubuntu 8.04 LTS
login - 1:
Ubuntu 7.10
login - 1:
Ubuntu 6.06 LTS
login - 1:4.0.13-7ubuntu3.4

To update your system, please follow these instructions:

In general, a standard system upgrade is sufficient to effect the necessary changes.