X.Org X Window System (aka X11 and X) X11R5 and X.Org Server (aka xserver and xorg-server) before 1.16.3, when using SUN-DES-1 (Secure RPC) authentication credentials, does not check the return value of a malloc call, which allows remote attackers to cause a denial of service (NULL pointer dereference and server crash) via a crafted connection request.
https://security.gentoo.org/glsa/201504-06
http://www.x.org/wiki/Development/Security/Advisory-2014-12-09/
http://www.securityfocus.com/bid/71597
http://www.oracle.com/technetwork/topics/security/cpujul2015-2367936.html
http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html
http://www.oracle.com/technetwork/topics/security/bulletinjan2015-2370101.html
http://www.mandriva.com/security/advisories?name=MDVSA-2015:119
http://www.debian.org/security/2014/dsa-3095
http://secunia.com/advisories/62292