qpopper POP server creates lock files with predictable names, which allows local users to cause a denial of service for other users (lack of mail access) by creating lock files for other mail boxes.

POP2 or POP3 server (pop3d) in imap-uw IMAP package on FreeBSD and other operating systems creates lock files with predictable names, which allows local users to cause a denial of service (lack of mail access) for other users by creating lock files f