Several security issues were fixed in the GNU C Library.
Arnaud Le Blanc discovered that the GNU C Library incorrectly handled file descriptors when resolving DNS queries under high load. This may cause a denial of service in other applications, or an information leak. This issue only affected Ubuntu 10.04 LTS, Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2013-7423)
26 February 2015
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the GNU C Library.
Arnaud Le Blanc discovered that the GNU C Library incorrectly handled file descriptors when resolving DNS queries under high load. This may cause a denial of service in other applications, or an information leak. This issue only affected Ubuntu 10.04 LTS, Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2013-7423)
It was discovered that the GNU C Library incorrectly handled receiving a positive answer while processing the network name when performing DNS resolution. A remote attacker could use this issue to cause the GNU C Library to hang, resulting in a denial of service. (CVE-2014-9402)
Joseph Myers discovered that the GNU C Library wscanf function incorrectly handled memory. A remote attacker could possibly use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 12.04 LTS, Ubuntu 14.04 LTS and Ubuntu 14.10. (CVE-2015-1472, CVE-2015-1473)
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.
After a standard system update you need to reboot your computer to make all the necessary changes.