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.
https://exchange.xforce.ibmcloud.com/vulnerabilities/70336
http://www.securitytracker.com/id?1026144
http://www.securityfocus.com/bid/49957
http://www.redhat.com/support/errata/RHSA-2011-1392.html
http://www.redhat.com/support/errata/RHSA-2011-1391.html
http://www.oracle.com/technetwork/topics/security/cpujul2012-392727.html
http://www.oracle.com/technetwork/topics/security/cpujan2015-1972971.html
http://www.mandriva.com/security/advisories?name=MDVSA-2013:150
http://www.mandriva.com/security/advisories?name=MDVSA-2011:144
http://www.exploit-db.com/exploits/17969
http://www.debian.org/security/2012/dsa-2405
http://www.contextis.com/research/blog/reverseproxybypass/
http://www-01.ibm.com/support/docview.wss?uid=nas2b7c57b1f1035675186257927003c8d48
http://www-01.ibm.com/support/docview.wss?uid=nas2064c7e5f53452ff686257927003c8d42
http://svn.apache.org/viewvc?view=revision&revision=1179239
http://support.apple.com/kb/HT5501
http://secunia.com/advisories/48551
http://secunia.com/advisories/46414
http://secunia.com/advisories/46288
http://seclists.org/fulldisclosure/2011/Oct/273
http://seclists.org/fulldisclosure/2011/Oct/232
http://rhn.redhat.com/errata/RHSA-2012-0543.html
http://rhn.redhat.com/errata/RHSA-2012-0542.html
http://marc.info/?l=bugtraq&m=134987041210674&w=2
http://marc.info/?l=bugtraq&m=133294460209056&w=2
http://lists.opensuse.org/opensuse-updates/2013-02/msg00012.html
http://lists.opensuse.org/opensuse-updates/2013-02/msg00009.html
http://lists.opensuse.org/opensuse-security-announce/2011-11/msg00011.html
http://lists.apple.com/archives/security-announce/2012/Sep/msg00004.html