The netsnmp_udp_fmtaddr function (snmplib/snmpUDPDomain.c) in net-snmp 5.0.9 through 5.4.2.1, when using TCP wrappers for client authorization, does not properly parse hosts.allow rules, which allows remote attackers to bypass intended access restrictions and execute SNMP queries, related to "source/destination IP address confusion."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10289
https://euvd.enisa.europa.eu/vulnerability/EUVD-2008-6093
https://bugzilla.redhat.com/show_bug.cgi?id=485211
http://www.securitytracker.com/id?1021921
http://www.redhat.com/support/errata/RHSA-2009-0295.html
http://www.openwall.com/lists/oss-security/2009/02/12/7
http://www.openwall.com/lists/oss-security/2009/02/12/4
http://www.openwall.com/lists/oss-security/2009/02/12/2
http://secunia.com/advisories/35685
http://secunia.com/advisories/35416
http://secunia.com/advisories/34499
http://net-snmp.svn.sourceforge.net/viewvc/net-snmp?view=rev&revision=17367
http://lists.opensuse.org/opensuse-security-announce/2010-02/msg00003.html
http://lists.opensuse.org/opensuse-security-announce/2009-07/msg00002.html
http://lists.opensuse.org/opensuse-security-announce/2009-06/msg00003.html