Buffer overflow in CVS before 1.11.20 allows remote attackers to execute arbitrary code.
CVS 1.12 and earlier on Debian GNU/Linux, when using the repouid patch, allows remote attackers to bypass authentication via the pserver access method.
CVS 1.11.x before 1.11.17, and 1.12.x before 1.12.9, allows remote attackers to determine the existence of arbitrary files and directories via the -X command for an alternate history file, which causes different error messages to be returned.