The GD library could be made to crash or run programs if it processed a specially crafted image file.
Ibrahim El-Sayed discovered that the GD library incorrectly handled certain malformed Tiff images. If a user or automated system were tricked into processing a specially crafted Tiff image, an attacker could cause a denial of service. (CVE-2016-6911)
1 November 2016
A security issue affects these releases of Ubuntu and its derivatives:
The GD library could be made to crash or run programs if it processed a specially crafted image file.
Ibrahim El-Sayed discovered that the GD library incorrectly handled certain malformed Tiff images. If a user or automated system were tricked into processing a specially crafted Tiff image, an attacker could cause a denial of service. (CVE-2016-6911)
Ke Liu discovered that the GD library incorrectly handled certain integers when processing WebP images. If a user or automated system were tricked into processing a specially crafted WebP image, an attacker could cause a denial of service, or possibly execute arbitrary code. This issue only applied to Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-7568)
Emmanuel Law discovered that the GD library incorrectly handled certain strings when creating images. If a user or automated system were tricked into processing a specially crafted image, an attacker could cause a denial of service, or possibly execute arbitrary code. (CVE-2016-8670)
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.