USN-881-1: Kerberos vulnerability

Ubuntu Security Notice USN-881-1

12th January, 2010

krb5 vulnerability

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

  • Ubuntu 9.10
  • Ubuntu 9.04
  • Ubuntu 8.10
  • Ubuntu 8.04 LTS
  • Ubuntu 6.06 LTS

Software description

  • krb5


It was discovered that Kerberos did not correctly handle invalid AES
blocks. An unauthenticated remote attacker could send specially crafted
traffic that would crash the KDC service, leading to a denial of service,
or possibly execute arbitrary code with root privileges.

Update instructions

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

Ubuntu 9.10:
libk5crypto3 1.7dfsg~beta3-1ubuntu0.3
Ubuntu 9.04:
libkrb53 1.6.dfsg.4~beta1-5ubuntu2.2
Ubuntu 8.10:
libkrb53 1.6.dfsg.4~beta1-3ubuntu0.3
Ubuntu 8.04 LTS:
libkrb53 1.6.dfsg.3~beta1-2ubuntu1.3
Ubuntu 6.06 LTS:
libkrb53 1.4.3-5ubuntu0.10

To update your system, please follow these instructions:

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