=========================================================================Ubuntu Security Notice USN-4107-1
August 20, 2019

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

- Ubuntu 19.04
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in GIFLIB.

Software Description:
- giflib: library for GIF images (utilities)

Details:

It was discovered that GIFLIB incorrectly handled certain GIF files.
An attacker could possibly use this issue to cause a denial of service.
This issue only affected Ubuntu 18.04 LTS. (CVE-2016-3977)

It was discovered that GIFLIB incorrectly handled certain GIF files.
An attacker could possibly use this issue to cause a denial of service.
(CVE-2018-11490, CVE-2019-15133)

Update instructions:

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

Ubuntu 19.04:
  giflib-tools                    5.1.4-3ubuntu0.1
  libgif7                         5.1.4-3ubuntu0.1

Ubuntu 18.04 LTS:
  giflib-tools                    5.1.4-2ubuntu0.1
  libgif7                         5.1.4-2ubuntu0.1

Ubuntu 16.04 LTS:
  giflib-tools                    5.1.4-0.3~16.04.1
  libgif7                         5.1.4-0.3~16.04.1

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

References:
  https://ubuntu.com/security/notices/USN-4107-1
  CVE-2016-3977, CVE-2018-11490, CVE-2019-15133

Package Information:
  https://launchpad.net/ubuntu/+source/giflib/5.1.4-3ubuntu0.1
  https://launchpad.net/ubuntu/+source/giflib/5.1.4-2ubuntu0.1
  https://launchpad.net/ubuntu/+source/giflib/5.1.4-0.3~16.04.1