gnuserv before 3.12, as shipped with XEmacs, does not properly check the specified length of an X Windows MIT-MAGIC-COOKIE cookie, which allows remote attackers to execute arbitrary commands via a buffer overflow, or brute force authentication by using a short cookie length.
AV:N/AC:L/Au:N/C:C/I:C/A:C
This vulnerability has a 5.50% probability of being exploited in the next 30 days, ranking higher than 93% of all scored CVEs.