The mod_proxy module in the Apache HTTP Server 1.3.x through 1.3.42, 2.0.x through 2.0.64, and 2.2.x through 2.2.21 does not properly interact with use of (1) RewriteRule and (2) ProxyPassMatch pattern matches for configuration of a reverse proxy, which allows remote attackers to send requests to intranet servers via a malformed URI containing an initial @ (at sign) character.
http://kb.juniper.net/JSA10585
http://lists.apple.com/archives/security-announce/2012/Sep/msg00004.html
http://lists.opensuse.org/opensuse-security-announce/2011-11/msg00011.html
http://lists.opensuse.org/opensuse-updates/2013-02/msg00009.html
http://lists.opensuse.org/opensuse-updates/2013-02/msg00012.html
http://marc.info/?l=bugtraq&m=133294460209056&w=2
http://marc.info/?l=bugtraq&m=134987041210674&w=2
http://rhn.redhat.com/errata/RHSA-2012-0542.html
http://rhn.redhat.com/errata/RHSA-2012-0543.html
https://bugzilla.redhat.com/show_bug.cgi?id=740045
http://seclists.org/fulldisclosure/2011/Oct/232
http://seclists.org/fulldisclosure/2011/Oct/273
http://secunia.com/advisories/46288
http://secunia.com/advisories/46414
http://secunia.com/advisories/48551
https://exchange.xforce.ibmcloud.com/vulnerabilities/70336
http://support.apple.com/kb/HT5501
http://svn.apache.org/viewvc?view=revision&revision=1179239
http://www-01.ibm.com/support/docview.wss?uid=nas2064c7e5f53452ff686257927003c8d42
http://www-01.ibm.com/support/docview.wss?uid=nas2b7c57b1f1035675186257927003c8d48
http://www.debian.org/security/2012/dsa-2405
http://www.exploit-db.com/exploits/17969
http://www.mandriva.com/security/advisories?name=MDVSA-2011:144
http://www.mandriva.com/security/advisories?name=MDVSA-2013:150
http://www.oracle.com/technetwork/topics/security/cpujan2015-1972971.html
http://www.oracle.com/technetwork/topics/security/cpujul2012-392727.html
http://www.redhat.com/support/errata/RHSA-2011-1391.html