Buffer overflow in X.org libXt 1.1.3 and earlier allows X servers to cause a denial of service (crash) and possibly execute arbitrary code via crafted length or index values to the _XtResourceConfigurationEH function.
http://lists.fedoraproject.org/pipermail/package-announce/2013-May/106785.html
http://lists.opensuse.org/opensuse-updates/2013-06/msg00138.html
http://www.debian.org/security/2013/dsa-2680