X.Org server (xorg-server) 1.0.0 and later, X11R6.9.0, and X11R7.0 inadvertently treats the address of the geteuid function as if it is the return value of a call to geteuid, which allows local users to bypass intended restrictions and (1) execute arbitrary code via the -modulepath command line option or (2) overwrite arbitrary files via -logfile.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A1697
https://exchange.xforce.ibmcloud.com/vulnerabilities/25341
http://www.vupen.com/english/advisories/2006/1028
http://www.vupen.com/english/advisories/2006/1017
http://www.securityfocus.com/archive/1/428230/100/0/threaded
http://www.securityfocus.com/archive/1/428183/100/0/threaded
http://www.redhat.com/archives/fedora-announce-list/2006-March/msg00026.html
http://www.novell.com/linux/security/advisories/2006_16_xorgx11server.html
http://www.mandriva.com/security/advisories?name=MDKSA-2006:056
http://support.avaya.com/elmodocs2/security/ASA-2006-078.htm
http://sunsolve.sun.com/search/document.do?assetkey=1-26-102252-1
http://securitytracker.com/id?1015793
http://securityreason.com/securityalert/606
http://secunia.com/advisories/19676
http://secunia.com/advisories/19316
http://secunia.com/advisories/19311