USN-3009-1: Dnsmasq vulnerability

20 June 2016

dnsmasq vulnerability

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

  • Ubuntu 16.04 LTS
  • Ubuntu 15.10


Dnsmasq could be made to crash if it received specially crafted network traffic.

Software Description

  • dnsmasq - Small caching DNS proxy and DHCP/TFTP server


Edwin Török discovered that Dnsmasq incorrectly handled certain CNAME responses. A remote attacker could use this issue to cause Dnsmasq to crash, resulting in a denial of service.

Update instructions

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

Ubuntu 16.04 LTS
dnsmasq - 2.75-1ubuntu0.16.04.1
dnsmasq-base - 2.75-1ubuntu0.16.04.1
dnsmasq-utils - 2.75-1ubuntu0.16.04.1
Ubuntu 15.10
dnsmasq - 2.75-1ubuntu0.15.10.1
dnsmasq-base - 2.75-1ubuntu0.15.10.1
dnsmasq-utils - 2.75-1ubuntu0.15.10.1

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.