Race condition in the Xsession script, as used by X Display Manager (xdm) in NetBSD before 20060212, X.Org before 20060225, and Solaris 8 through 10 before 20061006, causes a user's Xsession errors file to have weak permissions before a chmod is performed, which allows local users to read Xsession errors files of other users.
https://bugs.freedesktop.org/show_bug.cgi?id=5897
http://secunia.com/advisories/22323
http://secunia.com/advisories/22439
http://secunia.com/advisories/22469
http://secunia.com/advisories/22992
http://securitytracker.com/id?1017015
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A1760
http://sunsolve.sun.com/search/document.do?assetkey=1-26-102652-1
http://support.avaya.com/elmodocs2/security/ASA-2006-250.htm