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.
The X Display Manager Control Protocol (XDMCP) support for GDM before 2.4.1.6 allows attackers to cause a denial of service (daemon crash) when a chosen host expires, a different issue than CVE-2003-0549.
The X Display Manager Control Protocol (XDMCP) support for GDM before 2.4.1.6 allows attackers to cause a denial of service (daemon crash) via a short authorization key name.