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 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 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.