Fetchmail versions 6.3.9 and below suffer from a dereferencing garbage pointer vulnerability that can lead to a denial of service condition.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/67409/fetchmail-SA-2008-01.txt
Source: https://packetstormsecurity.com/files/67409/fetchmail-SA-2008-01.txt.html