The system could be made to expose sensitive information.
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.
14 August 2017
A security issue affects these releases of Ubuntu and its derivatives:
The system could be made to expose sensitive information.
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.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.
Vulmon