GDM 2.4.4.x before 2.4.4.4, and 2.4.1.x before 2.4.1.7, does not limit the number or duration of commands and uses a blocking socket connection, which allows attackers to cause a denial of service (resource exhaustion) by sending commands and not reading the results.

GDM 2.4.4.x before 2.4.4.4, and 2.4.1.x before 2.4.1.7, does not restrict the size of input, which allows attackers to cause a denial of service (memory consumption).

GDM before 2.4.1.6, when using the "examine session errors" feature, allows local users to read arbitrary files via a symlink attack on the ~/.xsession-errors file.

Error messages generated by gdm with the VerboseAuth setting allows an attacker to identify valid users on a system.

GNOME GDM 2.8, 2.12, 2.14, and 2.15, when the "face browser" feature is enabled, allows local users to access the "Configure Login Manager" functionality using their own password instead of the root password, which can be leveraged to gain additional privileges.

Race condition in daemon/slave.c in gdm before 2.14.1 allows local users to gain privileges via a symlink attack when gdm performs chown and chgrp operations on the .ICEauthority file.

The GDM daemon in GNOME Display Manager (GDM) before 2.14.13, 2.16.x before 2.16.7, 2.18.x before 2.18.4, and 2.19.x before 2.19.5 does not properly handle NULL return values from the gstrsplit function, which allows local users to cause a denial of service (persistent daemon crash) via a crafted command to the daemon's socket, related to (1) gdm.c and (2) gdmconfig.c in daemon/, and (3) gdmconfig.c and (4) gdmflexiserver.c in gui/.