CVS 1.12.x through 1.12.8, and 1.11.x through 1.11.16, does not properly handle malformed "Entry" lines, which prevents a NULL terminator from being used and may lead to a denial of service (crash), modification of critical program data, or arbitrary code execution.

Heap-based buffer overflow in CVS 1.11.x up to 1.11.15, and 1.12.x up to 1.12.7, when using the pserver mechanism allows remote attackers to execute arbitrary code via Entry lines.

CVS server before 1.11.10 may allow attackers to cause the CVS server to create directories and files in the file system root directory via malformed module requests.

Double-free vulnerability in CVS 1.11.4 and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary code via a malformed Directory request, as demonstrated by bypassing write checks to execute Update-prog and Checkin-prog commands.