Updated GD packages has been released for Ubuntu 12.04 ESM (Extended Security Maintenance). A paid service for Ubuntu Advantage customers who can not upgrade to a newer version of Ubuntu Server

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Ubuntu Security Notice USN-3389-2
August 14, 2017

libgd2 vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 12.04 ESM

Summary:

The system could be made to expose sensitive information.

Software Description:
- libgd2: GD Graphics Library

Details:

USN-3389-1 fixed a vulnerability in GD Graphics Library.
This update provides the corresponding update for Ubuntu 12.04 ESM.

Original advisory details:

 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 12.04 ESM:
  libgd-tools