Mandrake Linux Security Advisory : fetchmail (MDKSA-2007:105)
Low Nessus Plugin ID 25265
SynopsisThe remote Mandrake Linux host is missing one or more security updates.
DescriptionThe APOP functionality in fetchmail's POP3 client implementation was validating the APOP challenge too lightly, accepting random garbage as a POP3 server's APOP challenge, rather than insisting it conform to RFC-822 specifications.
As a result of this flaw, it made man-in-the-middle attacks easier than necessary to retrieve the first few characters of the APOP secret, allowing them to potentially brute force the remaining characters easier than should be possible.
Updated packages have been patched to prevent these issues, however it should be noted that the APOP MD5-based authentication scheme should no longer be considered secure.
SolutionUpdate the affected fetchmail, fetchmail-daemon and / or fetchmailconf packages.