CVE-2011-3639

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...

4.3 MediumPublic exploitFix available

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.

Exploit likelihood

49.7%Up 43.2 points since Feb 4, 2022

What each source reports

NVD Score used 4.3

Record: CVE-2011-3639
CVSS 2.0: 4.3 MediumAV:N/AC:M/Au:N/C:N/I:P/A:N
Weakness: CWE-20
Updated: 2026-11-02

CVE List No score

Record: CVE-2011-3639
Updated: 2026-11-02

EUVDEUVD-2011-3598 No score

Record: EUVD-2011-3598
Updated: 2026-11-03

GitHub AdvisoriesGHSA-rqg3-pfxx-wwq3 No score

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...

Record: GHSA-rqg3-pfxx-wwq3
Weakness: CWE-20
Updated: 2026-11-02

OSVBELL-CVE-2011-3639 4.3

CVE-2011-3639 does not affect BellSoft software

Record: BELL-CVE-2011-3639
CVSS 2.0: 4.3 MediumAV:N/AC:M/Au:N/C:N/I:P/A:N
Updated: 2026-11-02

OSV No score

Record: CVE-2011-3639
Updated: 2026-11-02

OSVDEBIAN-CVE-2011-3639 No score

Record: DEBIAN-CVE-2011-3639
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`apache2` Debian:12	before 2.2.18-1	2.2.18-1
`apache2` Debian:13	before 2.2.18-1	2.2.18-1
`apache2` Debian:14	before 2.2.18-1	2.2.18-1
`apache2` Debian:6.0 From an advisory covering 6 CVEs	before 2.2.16-6+squeeze6, plus listed versions 2.2.16-62.2.16-6+squeeze12.2.16-6+squeeze1~bpo50+12.2.16-6+squeeze22.2.16-6+squeeze2~bpo50+12.2.16-6+squeeze32.2.16-6+squeeze42.2.16-6+squeeze4~bpo50+1	2.2.16-6+squeeze6
`apache2` Debian:5.0 From an advisory covering 6 CVEs	before 2.2.9-10+lenny12, plus listed versions 2.2.9-10+lenny102.2.9-10+lenny112.2.9-10+lenny22.2.9-10+lenny32.2.9-10+lenny4 Show 5 moreShow less 2.2.9-10+lenny52.2.9-10+lenny62.2.9-10+lenny72.2.9-10+lenny82.2.9-10+lenny9	2.2.9-10+lenny12
`httpd` Red Hat:enterprise_linux:6::client From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-debuginfo` Red Hat:enterprise_linux:6::client From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-tools` Red Hat:enterprise_linux:6::client From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-devel` Red Hat:enterprise_linux:6::client From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-manual` Red Hat:enterprise_linux:6::client From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1

Show 31 moreShow less

Affected packages
Package	Affected	Fixed
`mod_ssl` Red Hat:enterprise_linux:6::client From an advisory covering 5 CVEs	before 1:2.2.15-15.el6_2.1	1:2.2.15-15.el6_2.1
`httpd` Red Hat:enterprise_linux:6::computenode From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-debuginfo` Red Hat:enterprise_linux:6::computenode From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-tools` Red Hat:enterprise_linux:6::computenode From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-devel` Red Hat:enterprise_linux:6::computenode From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-manual` Red Hat:enterprise_linux:6::computenode From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`mod_ssl` Red Hat:enterprise_linux:6::computenode From an advisory covering 5 CVEs	before 1:2.2.15-15.el6_2.1	1:2.2.15-15.el6_2.1
`httpd` Red Hat:enterprise_linux:6::server From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-debuginfo` Red Hat:enterprise_linux:6::server From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-devel` Red Hat:enterprise_linux:6::server From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-manual` Red Hat:enterprise_linux:6::server From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-tools` Red Hat:enterprise_linux:6::server From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`mod_ssl` Red Hat:enterprise_linux:6::server From an advisory covering 5 CVEs	before 1:2.2.15-15.el6_2.1	1:2.2.15-15.el6_2.1
`httpd` Red Hat:enterprise_linux:6::workstation From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-debuginfo` Red Hat:enterprise_linux:6::workstation From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-devel` Red Hat:enterprise_linux:6::workstation From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-manual` Red Hat:enterprise_linux:6::workstation From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`httpd-tools` Red Hat:enterprise_linux:6::workstation From an advisory covering 5 CVEs	before 0:2.2.15-15.el6_2.1	0:2.2.15-15.el6_2.1
`mod_ssl` Red Hat:enterprise_linux:6::workstation From an advisory covering 5 CVEs	before 1:2.2.15-15.el6_2.1	1:2.2.15-15.el6_2.1
`httpd` Red Hat:enterprise_linux:5::client From an advisory covering 4 CVEs	before 0:2.2.3-63.el5_8.1	0:2.2.3-63.el5_8.1
`httpd-debuginfo` Red Hat:enterprise_linux:5::client From an advisory covering 4 CVEs	before 0:2.2.3-63.el5_8.1	0:2.2.3-63.el5_8.1
`mod_ssl` Red Hat:enterprise_linux:5::client From an advisory covering 4 CVEs	before 1:2.2.3-63.el5_8.1	1:2.2.3-63.el5_8.1
`httpd` Red Hat:enterprise_linux:5::client_workstation From an advisory covering 4 CVEs	before 0:2.2.3-63.el5_8.1	0:2.2.3-63.el5_8.1
`httpd-debuginfo` Red Hat:enterprise_linux:5::client_workstation From an advisory covering 4 CVEs	before 0:2.2.3-63.el5_8.1	0:2.2.3-63.el5_8.1
`httpd-devel` Red Hat:enterprise_linux:5::client_workstation From an advisory covering 4 CVEs	before 0:2.2.3-63.el5_8.1	0:2.2.3-63.el5_8.1
`httpd-manual` Red Hat:enterprise_linux:5::client_workstation From an advisory covering 4 CVEs	before 0:2.2.3-63.el5_8.1	0:2.2.3-63.el5_8.1
`httpd` Red Hat:enterprise_linux:5::server From an advisory covering 4 CVEs	before 0:2.2.3-63.el5_8.1	0:2.2.3-63.el5_8.1
`httpd-debuginfo` Red Hat:enterprise_linux:5::server From an advisory covering 4 CVEs	before 0:2.2.3-63.el5_8.1	0:2.2.3-63.el5_8.1
`httpd-devel` Red Hat:enterprise_linux:5::server From an advisory covering 4 CVEs	before 0:2.2.3-63.el5_8.1	0:2.2.3-63.el5_8.1
`httpd-manual` Red Hat:enterprise_linux:5::server From an advisory covering 4 CVEs	before 0:2.2.3-63.el5_8.1	0:2.2.3-63.el5_8.1
`mod_ssl` Red Hat:enterprise_linux:5::server From an advisory covering 4 CVEs	before 1:2.2.3-63.el5_8.1	1:2.2.3-63.el5_8.1

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
Exploit-DB	Apache 2.2.15 mod_proxy - Reverse Proxy Security Bypass	2012-02-06

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, Exploit-DB, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2011-3639 is a medium vulnerability (CVSS 4.3) in Apache Http Server, published November 30, 2011. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 49.7%, the 98th percentile. Fixed in apache2 2.2.18-1.

References

Show 28 moreShow less