SLiM Simple Login Manager 1.3.0 places the X authority magic cookie (mcookie) on the command line when invoking xauth from (1) app.cpp and (2) switchuser.cpp, which allows local users to access the X session by listing the process and its arguments.
bugs.debian.org/cgi-bin/bugreport.cgi?bug=529306
osvdb.org/54583
secunia.com/advisories/35132
secunia.com/advisories/38070
www.openwall.com/lists/oss-security/2009/05/18/2
www.securityfocus.com/bid/35015
exchange.xforce.ibmcloud.com/vulnerabilities/50611
www.redhat.com/archives/fedora-package-announce/2010-January/msg00000.html
www.redhat.com/archives/fedora-package-announce/2010-January/msg00009.html