USN-3434-2: Libidn vulnerability

Ubuntu Security Notice USN-3434-2

23rd October, 2017

libidn vulnerability

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

  • Ubuntu 12.04 LTS


Libidn could be made to crash or run programs if it processed specially crafted input.

Software description

  • libidn - implementation of IETF IDN specifications


USN-3434-1 fixed a vulnerability in Libidn. This update
provides the corresponding update for Ubuntu 12.04 ESM.

Original advisory details:

It was discovered that Libidn incorrectly handled decoding certain digits.
A remote attacker could use this issue to cause Libidn 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 12.04 LTS:
libidn11 1.23-2ubuntu0.2

To update your system, please follow these instructions:

In general, a standard system update will make all the necessary changes.