Description
The mod_proxy module in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x before 2.2.18, when the Revision 1179239 patch is in place, 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 by using the HTTP/0.9 protocol with a malformed URI containing an initial @ (at sign) character. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | apache2 | 2.2.18-1 | — |
| Debian 13 | apache2 | 2.2.18-1 | — |
| Debian 12 | apache2 | 2.2.18-1 | — |
| Debian 6.0 | apache2 | 2.2.16-6+squeeze6 | DSA-2405-1 |
| Debian 5.0 | apache2 | 2.2.9-10+lenny12 | DSA-2405-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | httpd +3 | 2.2.15-15.el6_2.1 | RHSA-2012:0128 |
| RHEL 6 | mod_ssl | 1:2.2.15-15.el6_2.1 | RHSA-2012:0128 |
| RHEL 5 | httpd +2 | 2.2.3-63.el5_8.1 | RHSA-2012:0323 |
| RHEL 5 | mod_ssl | 1:2.2.3-63.el5_8.1 | RHSA-2012:0323 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Exploit-DB 1
- Apache 2.2.15 mod_proxy - Reverse Proxy Security Bypass EDB-36663 · remote · Feb 6, 2012 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 3
- RHSA-2012:0323 Red Hat Security Advisory: httpd security update Red Hat Security Advisories (RHSA) · Aug 5, 2026
- RHSA-2012:0128 Red Hat Security Advisory: httpd security update Red Hat Security Advisories (RHSA) · Aug 5, 2026
- DSA-2405-1 apache2 - multiple issues Debian Security (DSA / DLA) · Mar 9, 2026
References
- https://bugzilla.redhat.com/show_bug.cgi?id=752080
- RHSA-2012:0128 vendor-advisory
- http://svn.apache.org/viewvc?view=revision&revision=1188745
- DSA-2405 vendor-advisory