Description
The Apache HTTP Server through 2.4.23 follows RFC 3875 section 4.1.18 and therefore does not protect applications from the presence of untrusted client data in the HTTP_PROXY environment variable, which might allow remote attackers to redirect an application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, aka an "httpoxy" issue. NOTE: the vendor states "This mitigation has been assigned the identifier CVE-2016-5387"; in other words, this is not a CVE ID for a vulnerability.
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 | 2.4.23-2 | — |
| Debian 13 | apache2 | 2.4.23-2 | — |
| Debian 12 | apache2 | 2.4.23-2 | — |
| Debian 8 | apache2 | 2.4.10-10+deb8u5 | DSA-3623-1 |
| Debian 7 | apache2 | 2.2.22-13+deb7u7 | DLA-553-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | apache2 | 2.4.18-2ubuntu3.1 | USN-3038-1 |
| Ubuntu 14.04 LTS | apache2 | 2.4.7-1ubuntu4.13 | USN-3038-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | httpd +5 | 2.4.6-40.el7_2.4 | RHSA-2016:1422 |
| RHEL 7 | mod_ssl +1 | 1:2.4.6-40.el7_2.4 | RHSA-2016:1422 |
| RHEL 6 | httpd +3 | 2.2.15-54.el6_8 | RHSA-2016:1421 |
| RHEL 6 | mod_ssl | 1:2.2.15-54.el6_8 | RHSA-2016:1421 |
| RHEL 5 | httpd +2 | 2.2.3-92.el5_11 | RHSA-2016:1421 |
| RHEL 5 | mod_ssl | 1:2.2.3-92.el5_11 | RHSA-2016:1421 |
| RHEL 2 | httpd24-httpd +5 | 2.4.18-11.el6 | RHSA-2016:1420 |
| RHEL 2 | httpd24-mod_ssl +1 | 1:2.4.18-11.el6 | RHSA-2016:1420 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat JBoss Web Server 3 | httpd24 +5 | 2.4.6-62.ep7.el6 | RHSA-2016:1636, RHSA-2016:1635 |
| Red Hat JBoss Web Server 3 | mod_ssl24 +1 | 1:2.4.6-62.ep7.el6 | RHSA-2016:1636, RHSA-2016:1635 |
| Red Hat JBoss Web Server 3 | tomcat7 +9 | 7.0.59-51_patch_01.ep7.el6 | RHSA-2016:1636, RHSA-2016:1635 |
| Red Hat JBoss Web Server 3 | tomcat8 +9 | 8.0.18-62_patch_01.ep7.el6 | RHSA-2016:1636, RHSA-2016:1635 |
| Red Hat JBoss Web Server 2 | httpd +3 | 2.2.26-54.ep6.el6 | RHSA-2016:1649 |
| Red Hat JBoss Web Server 2 | httpd22 +3 | 2.2.26-56.ep6.el7 | RHSA-2016:1648 |
| Red Hat JBoss Web Server 2 | jbcs-httpd24 +1 | 1-3.jbcs.el6 | RHSA-2016:1649, RHSA-2016:1648 |
| Red Hat JBoss Web Server 2 | jbcs-httpd24-openssl +4 | 1:1.0.2h-4.jbcs.el6 | RHSA-2016:1649, RHSA-2016:1648 |
| Red Hat JBoss Web Server 2 | mod_cluster +2 | 1.2.13-1.Final_redhat_1.1.ep6.el6 | RHSA-2016:1649, RHSA-2016:1648 |
| Red Hat JBoss Web Server 2 | mod_cluster-native | 1.2.13-3.Final_redhat_2.ep6.el6 | RHSA-2016:1649, RHSA-2016:1648 |
| Red Hat JBoss Web Server 2 | mod_jk +2 | 1.2.41-2.redhat_3.ep6.el6 | RHSA-2016:1649, RHSA-2016:1648 |
| Red Hat JBoss Web Server 2 | mod_ssl | 1:2.2.26-54.ep6.el6 | RHSA-2016:1649 |
| Red Hat JBoss Web Server 2 | mod_ssl22 | 1:2.2.26-56.ep6.el7 | RHSA-2016:1648 |
| Red Hat JBoss Web Server 2 | tomcat-native | 1.1.34-5.redhat_1.ep6.el6 | RHSA-2016:1649, RHSA-2016:1648 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-httpd +7 | 2.4.6-77.SP1.jbcs.el6 | RHSA-2016:1851 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_ssl +1 | 1:2.4.6-77.SP1.jbcs.el6 | RHSA-2016:1851 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP1 | apache2 | 2.4.16-7.1 | SUSE-SU-2016:1818-1 |
| SLES 12 | apache2 | 2.4.10-14.17.1 | SUSE-SU-2016:2090-1 |
| SLES 11 SP4 | apache2 | 2.2.12-64.1 | SUSE-SU-2016:1819-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Studio Onsite 1.3 | apache2 | 2.2.12-64.1 | SUSE-SU-2016:1819-1 |
| SLES for SAP 12 SP1 | apache2 | 2.4.16-7.1 | SUSE-SU-2016:1818-1 |
| SLES for SAP 12 | apache2 | 2.4.10-14.17.1 | SUSE-SU-2016:2090-1 |
| SLES for SAP 11 SP4 | apache2 | 2.2.12-64.1 | SUSE-SU-2016:1819-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | apache2 | 2.4.49-1.1 | openSUSE-SU-2024:10623-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.4 | apache2 | 2.4.23-r1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | httpd +5 | 2.4.6-40.0.1.el7_2.4 | ELSA-2016-1422 |
| Oracle Linux 7 | mod_ssl +1 | 1:2.4.6-40.0.1.el7_2.4 | ELSA-2016-1422 |
Advisories 18
- RHSA-2016:1851 Red Hat Security Advisory: Red Hat JBoss Core Services Apache HTTP 2.4.6 Service Pack 1 security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2016:1648 Red Hat Security Advisory: Red Hat JBoss Web Server 2.1.1 security update on RHEL 7 Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2016:1649 Red Hat Security Advisory: Red Hat JBoss Web Server 2.1.1 security update on RHEL 6 Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2016:1635 Red Hat Security Advisory: Red Hat JBoss Web Server 3.0.3 Service Pack 1 security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2016:1636 Red Hat Security Advisory: Red Hat JBoss Web Server 3.0.3 Service Pack 1 security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2016:1422 Red Hat Security Advisory: httpd security and bug fix update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2016:1421 Red Hat Security Advisory: httpd security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2016:1420 Red Hat Security Advisory: httpd24-httpd security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- USN-3038-1 apache2 vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-553-1 apache2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3623-1 apache2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2016:1819-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2090-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10623-1 apache2-2.4.49-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2025-2522 Mehrere Webserver: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen BSI CERT-Bund (WID) · Nov 10, 2025
- SUSE-SU-2016:1818-1 Security update for apache2 SUSE / openSUSE Security Updates · May 2, 2025
- WID-SEC-2025-0370 Apple Mac OS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 13, 2025
- ELSA-2016-1422 Important: httpd security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jul 18, 2016
References
- 1036330 vdb-entry
- RHSA-2016:1420 vendor-advisory
- RHSA-2016:1635 vendor-advisory
- https://support.apple.com/HT208221
- https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05320149
- 91816 vdb-entry
- RHSA-2016:1851 vendor-advisory
- USN-3038-1 vendor-advisory
- VU#797896 third-party-advisory
- http://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html
- openSUSE-SU-2016:1824 vendor-advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinjul2016-3090544.html
- RHSA-2016:1648 vendor-advisory
- https://www.tenable.com/security/tns-2017-04
- RHSA-2016:1625 vendor-advisory
- DSA-3623 vendor-advisory
- RHSA-2016:1649 vendor-advisory
- https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05390722
- https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03770en_us
- RHSA-2016:1422 vendor-advisory
- http://www.oracle.com/technetwork/topics/security/bulletinoct2016-3090566.html
- RHSA-2016:1421 vendor-advisory
- FEDORA-2016-a29c65b00f vendor-advisory
- RHSA-2016:1650 vendor-advisory
- RHSA-2016:1624 vendor-advisory
- https://www.apache.org/security/asf-httpoxy-response.txt
- FEDORA-2016-df0726ae26 vendor-advisory
- https://httpoxy.org/
- http://www.oracle.com/technetwork/security-advisory/cpujul2017-3236622.html
- GLSA-201701-36 vendor-advisory
- RHSA-2016:1636 vendor-advisory
- FEDORA-2016-9fd9bfab9e vendor-advisory
- FEDORA-2016-683d0b257b vendor-advisory
- [httpd-cvs] 20190815 svn commit: r1048743 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20190815 svn commit: r1048742 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20190815 svn commit: r1048743 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20190815 svn commit: r1048742 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20200401 svn commit: r1058586 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20200401 svn commit: r1058586 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20200401 svn commit: r1058587 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20200401 svn commit: r1058587 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20210330 svn commit: r1073139 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073140 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.ht mailing-list
- [httpd-cvs] 20210330 svn commit: r1073140 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.ht mailing-list
- [httpd-cvs] 20210330 svn commit: r1888194 [10/13] - /httpd/site/trunk/content/security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073139 [10/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073146 [2/3] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities-httpd.xml security/vulnerabilities_22.html security/vulnerabilities_24.html mailing-list
- [httpd-cvs] 20210330 svn commit: r1073149 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073146 [3/3] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities-httpd.xml security/vulnerabilities_22.html security/vulnerabilities_24.html mailing-list
- [httpd-cvs] 20210330 svn commit: r1073149 [10/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ mailing-list
- [httpd-cvs] 20210603 svn commit: r1075360 [2/3] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2021-31618.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabiliti mailing-list
- [httpd-cvs] 20210603 svn commit: r1075360 [3/3] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2021-31618.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabiliti mailing-list
- [httpd-cvs] 20210606 svn commit: r1075467 [2/2] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2021-31618.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabiliti mailing-list
- [httpd-cvs] 20210606 svn commit: r1075470 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2020-13938.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabiliti mailing-list