Ubuntu Security Notice USN-334-1
16th 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
Details
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 version:
- Ubuntu 6.06 LTS:
- krb5-clients 1.4.3-5ubuntu0.1
- krb5-rsh-server 1.4.3-5ubuntu0.1
- krb5-ftpd 1.4.3-5ubuntu0.1
- krb5-user 1.4.3-5ubuntu0.1
- Ubuntu 5.10:
- krb5-clients 1.3.6-4ubuntu0.1
- krb5-rsh-server 1.3.6-4ubuntu0.1
- krb5-ftpd 1.3.6-4ubuntu0.1
- krb5-user 1.3.6-4ubuntu0.1
- Ubuntu 5.04:
- krb5-clients 1.3.6-1ubuntu0.2
- krb5-rsh-server 1.3.6-1ubuntu0.2
- krb5-ftpd 1.3.6-1ubuntu0.2
- krb5-user 1.3.6-1ubuntu0.2
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system upgrade is sufficient to effect the
necessary changes.