OpenSSH 3.6.1 and earlier, when restricting host access by numeric IP addresses and with VerifyReverseMapping disabled, allows remote attackers to bypass "from=" and "user@host" address restrictions by connecting to a host from a system whose reverse DNS hostname contains the numeric IP address.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9894
http://www.vmware.com/support/vi3/doc/esx-9986131-patch.html
http://www.vmware.com/support/vi3/doc/esx-3069097-patch.html
http://www.securityfocus.com/bid/7831
http://www.redhat.com/support/errata/RHSA-2006-0698.html
http://www.redhat.com/support/errata/RHSA-2006-0298.html
http://support.avaya.com/elmodocs2/security/ASA-2006-174.htm
http://secunia.com/advisories/23680
http://secunia.com/advisories/22196
http://secunia.com/advisories/21724
http://secunia.com/advisories/21262
http://secunia.com/advisories/21129
http://lists.apple.com/mhonarc/security-announce/msg00038.html