USN-3389-1: GD vulnerability

14 August 2017

libgd2 vulnerability

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

  • Ubuntu 17.04
  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS


The system could be made to expose sensitive information.

Software Description

  • libgd2 - GD Graphics Library


A vulnerability was discovered in GD Graphics Library (aka libgd), as used in PHP that does not zero colorMap arrays before use. A specially crafted GIF image could use the uninitialized tables to read bytes from the top of the stack.

Update instructions

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

Ubuntu 17.04
libgd-tools - 2.2.4-2ubuntu0.2
Ubuntu 16.04 LTS
libgd-tools - 2.1.1-4ubuntu0.16.04.7
Ubuntu 14.04 LTS
libgd-tools - 2.1.0-3ubuntu0.7

To update your system, please follow these instructions:

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