eglibc, glibc vulnerabilities

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)