sink.c in fetchmail before 6.3.9 allows context-dependent attackers to cause a denial of service (NULL dereference and application crash) by refusing certain warning messages that are sent over SMTP.
fetchmail.berlios.de/fetchmail-SA-2007-02.txt
lists.apple.com/archives/security-announce/2009/Feb/msg00000.html
lists.opensuse.org/opensuse-security-announce/2007-10/msg00008.html
mknod.org/svn/fetchmail/branches/BRANCH_6-3/fetchmail-SA-2007-02.txt
osvdb.org/45833
secunia.com/advisories/27399
secunia.com/advisories/33937
securityreason.com/securityalert/3074
support.apple.com/kb/HT3438
www.debian.org/security/2007/dsa-1377
www.mandriva.com/security/advisories?name=MDKSA-2007:179
www.securityfocus.com/archive/1/478798/100/0/threaded
www.securityfocus.com/archive/1/493388/100/0/threaded
www.securityfocus.com/bid/25495
www.securitytracker.com/id?1018627
www.trustix.org/errata/2007/0028/
www.ubuntu.com/usn/usn-520-1
www.vupen.com/english/advisories/2007/3032
www.vupen.com/english/advisories/2009/0422
exchange.xforce.ibmcloud.com/vulnerabilities/36385
issues.rpath.com/browse/RPL-1690
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10528