dmrc.c in Light Display Manager (aka LightDM) before 1.1.1 allows local users to read arbitrary files via a symlink attack on ~/.dmrc.

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.

lightdm before 1.0.9 does not properly close file descriptors before opening a child process, which allows local users to write to the lightdm log or have other unspecified impact.

LightDM before 1.0.6 allows local users to change ownership of arbitrary files via a symlink attack on ~/.Xauthority.

Light Display Manager (aka LightDM) 1.4.x before 1.4.3, 1.6.x before 1.6.2, and 1.7.x before 1.7.14 uses 0664 permissions for the temporary .Xauthority file, which allows local users to obtain sensitive information by reading the file.

LightDM 1.7.5 through 1.8.3 and 1.9.x before 1.9.2 does not apply the AppArmor profile to the Guest account, which allows local users to bypass intended restrictions by leveraging the Guest account.