The version of Sendmail 8.13.1-2 on Red Hat Enterprise Linux 4 Update 4 and earlier does not reject the "localhost.localdomain" domain name for e-mail messages that come from external hosts, which might allow remote attackers to spoof messages.Referenceshttp://secunia.com/advisories/25098https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=171838http://www.redhat.com/support/errata/RHSA-2007-0252.htmlhttp://secunia.com/advisories/25743http://support.avaya.com/elmodocs2/security/ASA-2007-248.htmhttps://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11499http://www.securityfocus.com/bid/23742
