debian/guest-account in Light Display Manager (lightdm) 1.0.x before 1.0.6 and 1.1.x before 1.1.7, as used in Ubuntu Linux 11.10, allows local users to delete arbitrary files via a space in the name of a file in /tmp.  NOTE: this identifier was SPLIT per ADT1/ADT2 due to different codebases and affected versions. CVE-2012-6648 has been assigned for the gdm-guest-session issue.