USN-2900-1: GNU C Library vulnerability

Ubuntu Security Notice USN-2900-1

16th February, 2016

eglibc, glibc vulnerability

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

  • Ubuntu 15.10
  • Ubuntu 14.04 LTS
  • Ubuntu 12.04 LTS


GNU C Library could be made to crash or run programs if it received specially crafted network traffic.

Software description

  • eglibc - GNU C Library
  • glibc - GNU C Library


It was discovered that the GNU C Library incorrectly handled receiving
responses while performing DNS resolution. A remote attacker could use this
issue to cause the GNU C Library to crash, resulting in a denial of
service, or possibly execute arbitrary code.

Update instructions

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

Ubuntu 15.10:
libc6 2.21-0ubuntu4.1
Ubuntu 14.04 LTS:
libc6 2.19-0ubuntu6.7
Ubuntu 12.04 LTS:
libc6 2.15-0ubuntu10.13

To update your system, please follow these instructions:

After a standard system update you need to reboot your computer to make
all the necessary changes.