CVE-2011-4317
published 2011-11-30CVE-2011-4317: 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, when the Revision 1179239 patch is in…
PriorityP347medium4.3CVSS 2.0
AVNACMAuNCNIPAN
EXPLOIT
EPSS
59.60%
99.0th percentile
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, 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 via a malformed URI containing an @ (at sign) character and a : (colon) character in invalid positions. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.
Affected
99 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
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| apache | http_server | — | — |
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Detection & IOCsextracted from sources · hover to see the quote
- →Detect reverse proxy bypass attempts by inspecting HTTP request-URIs for malformed patterns containing an '@' (at sign) and ':' (colon) in invalid positions — indicative of CVE-2011-4317 exploitation attempts against mod_proxy. ↗
- →Flag HTTP requests where the request-URI does not start with '/' and contains a parsed scheme followed by a path beginning with '@' or ':', as these bypass the CVE-2011-3368 patch check (e.g., scheme='@localhost', path=':8880' or scheme='qualys', path='@qqq.qq.qualys.com'). ↗
- →Monitor Apache error logs for 'invalid request-URI' messages containing '@' characters, which indicate attempted exploitation of this vulnerability being blocked by a patched server. ↗
- →Vulnerable configurations include RewriteRule or ProxyPassMatch directives using catch-all patterns such as '^(.*)' — audit reverse proxy configs for these patterns as they are exploitable. ↗
- ·The vulnerability only exists when the Revision 1179239 patch (incomplete fix for CVE-2011-3368) is applied — unpatched servers are vulnerable to CVE-2011-3368 instead, and fully fixed servers (2.2.22+) are not affected by either. ↗
- ·Red Hat Enterprise Linux 4 and 5 are NOT affected due to differences in apr-util's URI parsing implementation — the older apr_uri_parse() always returns a NULL or '/'-prefixed path when a non-NULL scheme is present. ↗
- ·The bypass is only exploitable when mod_proxy is configured with overly broad RewriteRule or ProxyPassMatch patterns (e.g., '^(.*)'); tightly scoped proxy rules reduce exposure. ↗
CVSS provenance
nvdv2.04.3MEDIUMAV:N/AC:M/Au:N/C:N/I:P/A:N
osv5.0MEDIUM
vendor_debian5.0MEDIUM
vendor_redhat5.0MEDIUM
vendor_ubuntu4.4MEDIUM
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Ubuntu
Apache HTTP Server vulnerabilities
vendor_ubuntu·2012-02-16·CVSS 4.4
CVE-2011-3607 [MEDIUM] Apache HTTP Server vulnerabilities
Title: Apache HTTP Server vulnerabilities
Summary: Several security issues were fixed in the Apache HTTP Server.
It was discovered that the Apache HTTP Server incorrectly handled the
SetEnvIf .htaccess file directive. An attacker having write access to a
.htaccess file may exploit this to possibly execute arbitrary code.
(CVE-2011-3607)
Prutha Parikh discovered that the mod_proxy module did not properly
interact with the RewriteRule and ProxyPassMatch pattern matches in the
configuration of a reverse proxy. This could allow remote attackers to
contact internal webservers behind the proxy that were not intended for
external exposure. (CVE-2011-4317)
Rainer Canavan discovered that the mod_log_config module incorrectly
handled a certain format string when used with a threaded MPM. A remot
Red Hat
httpd: uri scheme bypass of the reverse proxy vulnerability CVE-2011-3368 fix
vendor_redhat·2011-11-23·CVSS 5.0
CVE-2011-4317 [MEDIUM] httpd: uri scheme bypass of the reverse proxy vulnerability CVE-2011-3368 fix
httpd: uri scheme bypass of the reverse proxy vulnerability CVE-2011-3368 fix
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, 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 via a malformed URI containing an @ (at sign) character and a : (colon) character in invalid positions. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.
Statement: This issue did not affect the versions of httpd as shipped with Red Hat Enterprise Linux 4 and 5 due to differences in apr-util's apr_uri_parse() implementation.
P
Debian
CVE-2011-4317: apache2 - The mod_proxy module in the Apache HTTP Server 1.3.x through 1.3.42, 2.0.x throu...
vendor_debian·2011·CVSS 5.0
CVE-2011-4317 [MEDIUM] CVE-2011-4317: apache2 - The mod_proxy module in the Apache HTTP Server 1.3.x through 1.3.42, 2.0.x throu...
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, 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 via a malformed URI containing an @ (at sign) character and a : (colon) character in invalid positions. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.
Scope: local
bookworm: resolved (fixed in 2.2.21-3)
bullseye: resolved (fixed in 2.2.21-3)
forky: resolved (fixed in 2.2.21-3)
sid: resolved (fixed in 2.2.21-3)
trixie: resolved (fixed in 2.2.21-3)
GHSA
GHSA-2m6p-rg3r-28gh: The mod_proxy module in the Apache HTTP Server 1
ghsa_unreviewed·2022-05-13·CVSS 5.0
CVE-2011-4317 [MEDIUM] CWE-20 GHSA-2m6p-rg3r-28gh: The mod_proxy module in the Apache HTTP Server 1
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, 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 via a malformed URI containing an @ (at sign) character and a : (colon) character in invalid positions. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.
OSV
CVE-2011-4317: The mod_proxy module in the Apache HTTP Server 1
osv·2011-11-30·CVSS 5.0
CVE-2011-4317 [MEDIUM] CVE-2011-4317: The mod_proxy module in the Apache HTTP Server 1
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, 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 via a malformed URI containing an @ (at sign) character and a : (colon) character in invalid positions. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.
No detection rules found.
HackerOne
Out-of-date Version (Apache)
hackerone·2019-12-02·CVSS 5.0
[MEDIUM] Out-of-date Version (Apache)
Out-of-date Version (Apache)
URL https://████████/
Identified Version 2.2.15 (contains 4 important and 10 other vulnerabilities)
Latest Version 2.2.31
Vulnerability Database Result is based on 27.10.2016 vulnerability database content.
Vulnerability Details
Link identified you are using an out-of-date version of Apache.
Impact
Since this is an old version of the software, it may be vulnerable to attacks.
Remedy
Please upgrade your installation of Apache to the latest stable version.
Remedy References
•Downloading the Apache HTTP Server
Known Vulnerabilities in this Version
Medium Apache mod_cache and mod_dav Request Handling Denial of Service Vulnerability
The mod_cache and mod_dav modules in the Apache HTTP Server allow remote attackers to cause a denial of service (process
Bugzilla
CVE-2011-3368 CVE-2012-0053 CVE-2012-0031 CVE-2012-0021 CVE-2011-3607 httpd: multiple vulnerabilities [fedora-all]
bugzilla·2012-01-27·CVSS 5.0
CVE-2011-3368 [MEDIUM] CVE-2011-3368 CVE-2012-0053 CVE-2012-0031 CVE-2012-0021 CVE-2011-3607 httpd: multiple vulnerabilities [fedora-all]
CVE-2011-3368 CVE-2012-0053 CVE-2012-0031 CVE-2012-0021 CVE-2011-3607 httpd: multiple vulnerabilities [fedora-all]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected Fedora
versions.
For comments that are specific to the vulnerability please use bugs filed
against "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When creating a Bodhi update request, please include this bug ID and the
bug IDs of this bug's parent bugs filed against the "Security Response"
product (the top-level CVE bugs). Please mention the CVE IDs being fixed
in the RPM changelog when available.
Bodhi update submission link:
https://admin.fedora
Bugzilla
CVE-2011-4317 httpd: uri scheme bypass of the reverse proxy vulnerability CVE-2011-3368 fix
bugzilla·2011-11-23·CVSS 5.0
CVE-2011-4317 [MEDIUM] CVE-2011-4317 httpd: uri scheme bypass of the reverse proxy vulnerability CVE-2011-3368 fix
CVE-2011-4317 httpd: uri scheme bypass of the reverse proxy vulnerability CVE-2011-3368 fix
Additional problems were discovered in the httpd fix for CVE-2011-3368 - a reverse proxy bypass flaw - tracked via bug #740045. Upstream mailing list post identifies following request forms, which are not handled correctly:
GET @localhost::8880 HTTP/1.0\r\n\r\n
GET qualys:@qqq.qq.qualys.com HTTP/1.0\r\n\r\n
Reference:
http://thread.gmane.org/gmane.comp.apache.devel/46440
Discussion:
External References:
https://community.qualys.com/blogs/securitylabs/2011/11/23/apache-reverse-proxy-bypass-issue
---
Well,
If I try this with a similar setup and post the request forms, I always get an error stating that the request-URI is invalid:
[Mon Nov 28 13:57:34 2011] [error] [client a.b.c.d] invalid req
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c03360041http://kb.juniper.net/JSA10585http://lists.apple.com/archives/security-announce/2012/Sep/msg00004.htmlhttp://lists.opensuse.org/opensuse-updates/2013-02/msg00009.htmlhttp://lists.opensuse.org/opensuse-updates/2013-02/msg00012.htmlhttp://marc.info/?l=bugtraq&m=133294460209056&w=2http://marc.info/?l=bugtraq&m=134987041210674&w=2http://rhn.redhat.com/errata/RHSA-2012-0128.htmlhttp://secunia.com/advisories/48551http://support.apple.com/kb/HT5501http://thread.gmane.org/gmane.comp.apache.devel/46440http://www.debian.org/security/2012/dsa-2405http://www.mandriva.com/security/advisories?name=MDVSA-2012:003http://www.mandriva.com/security/advisories?name=MDVSA-2013:150http://www.oracle.com/technetwork/topics/security/cpujan2015-1972971.htmlhttp://www.oracle.com/technetwork/topics/security/cpujul2012-392727.htmlhttp://www.securitytracker.com/id?1026353https://bugzilla.redhat.com/show_bug.cgi?id=756483https://community.qualys.com/blogs/securitylabs/2011/11/23/apache-reverse-proxy-bypass-issuehttps://lists.apache.org/thread.html/8d63cb8e9100f28a99429b4328e4e7cebce861d5772ac9863ba2ae6f%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/f7f95ac1cd9895db2714fa3ebaa0b94d0c6df360f742a40951384a53%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r05b5357d1f6bd106f41541ee7d87aafe3f5ea4dc3e9bde5ce09baff8%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r1d201e3da31a2c8aa870c8314623caef7debd74a13d0f25205e26f15%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r476d175be0aaf4a17680ef98c5153b4d336eaef76fb2224cc94c463a%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r57608dc51b79102f3952ae06f54d5277b649c86d6533dcd6a7d201f7%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r75cbe9ea3e2114e4271bbeca7aff96117b50c1b6eb7c4772b0337c1f%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r9b4b963760a3cb5a4a70c902f325c6c0337fe51d5b8570416f8f8729%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r9ea3538f229874c80a10af473856a81fbf5f694cd7f471cc679ba70b%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/rad01d817195e6cc871cb1d73b207ca326379a20a6e7f30febaf56d24%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/rdca61ae990660bacb682295f2a09d34612b7bb5f457577fe17f4d064%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/rfbaf647d52c1cb843e726a0933f156366a806cead84fbd430951591b%40%3Ccvs.httpd.apache.org%3Ehttp://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c03360041http://kb.juniper.net/JSA10585http://lists.apple.com/archives/security-announce/2012/Sep/msg00004.htmlhttp://lists.opensuse.org/opensuse-updates/2013-02/msg00009.htmlhttp://lists.opensuse.org/opensuse-updates/2013-02/msg00012.htmlhttp://marc.info/?l=bugtraq&m=133294460209056&w=2http://marc.info/?l=bugtraq&m=134987041210674&w=2http://rhn.redhat.com/errata/RHSA-2012-0128.htmlhttp://secunia.com/advisories/48551http://support.apple.com/kb/HT5501http://thread.gmane.org/gmane.comp.apache.devel/46440http://www.debian.org/security/2012/dsa-2405http://www.mandriva.com/security/advisories?name=MDVSA-2012:003http://www.mandriva.com/security/advisories?name=MDVSA-2013:150http://www.oracle.com/technetwork/topics/security/cpujan2015-1972971.htmlhttp://www.oracle.com/technetwork/topics/security/cpujul2012-392727.htmlhttp://www.securitytracker.com/id?1026353https://bugzilla.redhat.com/show_bug.cgi?id=756483https://community.qualys.com/blogs/securitylabs/2011/11/23/apache-reverse-proxy-bypass-issuehttps://lists.apache.org/thread.html/8d63cb8e9100f28a99429b4328e4e7cebce861d5772ac9863ba2ae6f%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/f7f95ac1cd9895db2714fa3ebaa0b94d0c6df360f742a40951384a53%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r05b5357d1f6bd106f41541ee7d87aafe3f5ea4dc3e9bde5ce09baff8%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r1d201e3da31a2c8aa870c8314623caef7debd74a13d0f25205e26f15%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r476d175be0aaf4a17680ef98c5153b4d336eaef76fb2224cc94c463a%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r57608dc51b79102f3952ae06f54d5277b649c86d6533dcd6a7d201f7%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r75cbe9ea3e2114e4271bbeca7aff96117b50c1b6eb7c4772b0337c1f%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r9b4b963760a3cb5a4a70c902f325c6c0337fe51d5b8570416f8f8729%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r9ea3538f229874c80a10af473856a81fbf5f694cd7f471cc679ba70b%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/rad01d817195e6cc871cb1d73b207ca326379a20a6e7f30febaf56d24%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/rdca61ae990660bacb682295f2a09d34612b7bb5f457577fe17f4d064%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3Ehttps://lists.apache.org/thread.html/rfbaf647d52c1cb843e726a0933f156366a806cead84fbd430951591b%40%3Ccvs.httpd.apache.org%3E
2011-11-30
Published