socket.c in fetchmail before 6.3.11 does not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

fetchmail 6.3.8 and earlier, when running in -v -v (aka verbose) mode, allows remote attackers to cause a denial of service (crash and persistent mail failure) via a malformed mail message with long headers, which triggers an erroneous dereference when using vsnprintf to format log messages.