USN-334-1: krb5 vulnerabilities

16 August 2006

krb5 vulnerabilities

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

  • Ubuntu 6.06 LTS
  • Ubuntu 5.10
  • Ubuntu 5.04

Software Description


Michael Calmer and Marcus Meissner discovered that several krb5 tools did not check the return values from setuid() system calls. On systems that have configured user process limits, it may be possible for an attacker to cause setuid() to fail via resource starvation. In that situation, the tools will not reduce their privilege levels, and will continue operation as the root user.

By default, Ubuntu does not ship with user process limits.

Please note that these packages are not officially supported by Ubuntu (they are in the ‘universe’ component of the archive).

Update instructions

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

Ubuntu 6.06 LTS
krb5-clients - 1.4.3-5ubuntu0.1
krb5-ftpd - 1.4.3-5ubuntu0.1
krb5-rsh-server - 1.4.3-5ubuntu0.1
krb5-user - 1.4.3-5ubuntu0.1
Ubuntu 5.10
krb5-clients - 1.3.6-4ubuntu0.1
krb5-ftpd - 1.3.6-4ubuntu0.1
krb5-rsh-server - 1.3.6-4ubuntu0.1
krb5-user - 1.3.6-4ubuntu0.1
Ubuntu 5.04
krb5-clients - 1.3.6-1ubuntu0.2
krb5-ftpd - 1.3.6-1ubuntu0.2
krb5-rsh-server - 1.3.6-1ubuntu0.2
krb5-user - 1.3.6-1ubuntu0.2

To update your system, please follow these instructions:

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