USN-308-1: shadow vulnerability

6 July 2006

shadow vulnerability

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

  • Ubuntu 6.06 LTS
  • Ubuntu 5.10
  • Ubuntu 5.04

Software Description


Ilja van Sprundel discovered that passwd, when called with the -f, -g, or -s option, did not check the result of the setuid() call. On systems that configure PAM limits for the maximum number of user processes, a local attacker could exploit this to execute chfn, gpasswd, or chsh with root privileges.

This does not affect the default configuration of Ubuntu.

Update instructions

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

Ubuntu 6.06 LTS
passwd - 1:4.0.13-7ubuntu3.1
Ubuntu 5.10
passwd - 1:4.0.3-37ubuntu10
Ubuntu 5.04
passwd - 1:4.0.3-30.7ubuntu16.1

To update your system, please follow these instructions:

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