fetchmail before 6.3.6-rc4 does not properly enforce TLS and may transmit cleartext passwords over unsecured links if certain circumstances occur, which allows remote attackers to obtain sensitive information via man-in-the-middle (MITM) attacks.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10566
https://issues.rpath.com/browse/RPL-919
http://www.vupen.com/english/advisories/2007/1470
http://www.vupen.com/english/advisories/2007/0088
http://www.vupen.com/english/advisories/2007/0087
http://www.us-cert.gov/cas/techalerts/TA07-109A.html
http://www.ubuntu.com/usn/usn-405-1
http://www.trustix.org/errata/2007/0007
http://www.securityfocus.com/bid/21903
http://www.securityfocus.com/archive/1/460528/100/0/threaded
http://www.securityfocus.com/archive/1/456115/100/0/threaded
http://www.redhat.com/support/errata/RHSA-2007-0018.html
http://www.openpkg.com/security/advisories/OpenPKG-SA-2007.004.html
http://www.novell.com/linux/security/advisories/2007_4_sr.html
http://www.mandriva.com/security/advisories?name=MDKSA-2007:016
http://www.debian.org/security/2007/dsa-1259
http://slackware.com/security/viewer.php?l=slackware-security&y=2007&m=slackware-security.517995
http://securitytracker.com/id?1017478
http://security.gentoo.org/glsa/glsa-200701-13.xml
http://secunia.com/advisories/24966
http://secunia.com/advisories/24284
http://secunia.com/advisories/24174
http://secunia.com/advisories/24151
http://secunia.com/advisories/24007
http://secunia.com/advisories/23923
http://secunia.com/advisories/23838
http://secunia.com/advisories/23804
http://secunia.com/advisories/23781
http://secunia.com/advisories/23714
http://secunia.com/advisories/23695
http://secunia.com/advisories/23631
http://lists.apple.com/archives/Security-announce/2007/Apr/msg00001.html
http://fetchmail.berlios.de/fetchmail-SA-2006-02.txt