The FCGI (aka Fast CGI) module 0.70 through 0.73 for Perl, as used by CGI::Fast, uses environment variable values from one request during processing of a later request, which allows remote attackers to bypass authentication via crafted HTTP headers.
bugs.debian.org/cgi-bin/bugreport.cgi?bug=607479
www.debian.org/security/2011/dsa-2327
www.mandriva.com/security/advisories?name=MDVSA-2012:001
www.openwall.com/lists/oss-security/2011/09/08/1
www.openwall.com/lists/oss-security/2011/09/08/2
www.securityfocus.com/bid/49549
bugzilla.redhat.com/show_bug.cgi?id=736604
exchange.xforce.ibmcloud.com/vulnerabilities/69709
hermes.opensuse.org/messages/13154637
hermes.opensuse.org/messages/13155253
rt.cpan.org/Public/Bug/Display.html?id=68380