CVE-2017-7358

In LightDM through 1.22.0, a directory traversal issue in debian/guest-account.sh allows local attackers to own arbitrary directory path locations and escalate privileges to root when the guest user logs out.

CVE-2011-3349

lightdm before 0.9.6 writes in .dmrc and Xauthority files using root permissions while the files are in user controlled folders. A local user can overwrite root-owned files via a symlink, which can allow possible privilege escalation.