Multiple integer overflows in X.Org X Window System (aka X11 or X) X11R1 and X.Org Server (aka xserver and xorg-server) before 1.16.3 allow remote authenticated users to cause a denial of service (crash) or possibly execute arbitrary code via a crafted request to the (1) ProcPutImage, (2) GetHosts, (3) RegionSizeof, or (4) REQUEST_FIXED_SIZE function, which triggers an out-of-bounds read or write.
https://security.gentoo.org/glsa/201504-06
http://www.x.org/wiki/Development/Security/Advisory-2014-12-09/
http://www.securityfocus.com/bid/71595
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.oracle.com/technetwork/topics/security/bulletinapr2015-2511959.html
http://www.mandriva.com/security/advisories?name=MDVSA-2015:119
http://www.debian.org/security/2014/dsa-3095
http://secunia.com/advisories/62292