USN-2098-2: LibYAML regression

Ubuntu Security Notice USN-2098-2

13th February, 2014

libyaml regression

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

  • Ubuntu 13.10
  • Ubuntu 12.10
  • Ubuntu 12.04 LTS


USN-2098-1 introduced a regression in LibYAML.

Software description

  • libyaml - Fast YAML 1.1 parser and emitter library


USN-2098-1 fixed a vulnerability in LibYAML. The security fix used
introduced a regression that caused parsing failures for certain valid YAML
files. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

Florian Weimer discovered that LibYAML incorrectly handled certain large
yaml documents. An attacker could use this issue to cause LibYAML to crash,
resulting in a denial of service, or possibly execute arbitrary code.

Update instructions

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

Ubuntu 13.10:
libyaml-0-2 0.1.4-2ubuntu0.13.10.2
Ubuntu 12.10:
libyaml-0-2 0.1.4-2ubuntu0.12.10.2
Ubuntu 12.04 LTS:
libyaml-0-2 0.1.4-2ubuntu0.12.04.2

To update your system, please follow these instructions:

After a standard system update you need to restart applications using
LibYAML to make all the necessary changes.


LP: 1279805