USN-678-2: GnuTLS regression

10 December 2008

gnutls12, gnutls13, gnutls26 regression

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

  • gnutls26
  • gnutls13
  • gnutls12


USN-678-1 fixed a vulnerability in GnuTLS. The upstream patch introduced a regression when validating certain certificate chains that would report valid certificates as untrusted. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

Martin von Gagern discovered that GnuTLS did not properly verify certificate chains when the last certificate in the chain was self-signed. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to view sensitive information. (CVE-2008-4989)

Update instructions

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

Ubuntu 8.10
libgnutls26 - 2.4.1-1ubuntu0.2
Ubuntu 8.04 LTS
libgnutls13 - 2.0.4-1ubuntu2.3
Ubuntu 7.10
libgnutls13 - 1.6.3-1ubuntu0.3
Ubuntu 6.06 LTS
libgnutls12 - 1.2.9-2ubuntu1.4

To update your system, please follow these instructions:

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