CVE-2016-5387
HighThe 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…
Published Jul 19, 2016 · Updated Sep 23, 2026 · Also known as ALPINE-CVE-2016-5387, DEBIAN-CVE-2016-5387, DLA-553-1, DSA-3623-1, SUSE-SU-2016:1818-1, SUSE-SU-2016:1819-1, SUSE-SU-2016:2090-1, UBUNTU-CVE-2016-5387, USN-3038-1
Key Facts
Patch immediately- CVE-2016-5387 is a high-severity vulnerability (CVSS 8.1 v3.1) affecting HTTP Server (Apache), System Management Homepage (Hp), Communications User Data Repository (Oracle) and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 56% probability of exploitation in the next 30 days.
- Fixed versions are available, including HTTP Server 2.2.31, apache2 2.2.12-64.1, apache2 2.2.22-13+deb7u7.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
8.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
56%
Higher than 99.0% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
Get the full CVE-2016-5387 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Affected Products
180 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HTTP ServerApache | See advisory | 2.2.31 |
| System Management HomepageHp | See advisory | 7.5.5.0 |
| Communications User Data RepositoryOracle | See advisory | 12.4 |
| Enterprise Manager Ops CenterOracle | 12.2.2, 12.3.2 | n/a |
| Jboss Core ServicesRedhat | 1.0 | n/a |
Patched Releases
HTTP Server
2.2.31
apache2
2.2.12-64.1, 2.2.22-13+deb7u7, 2.4.10-10+deb8u5, 2.4.10-14.17.1, 2.4.16-12.1, 2.4.16-7.1, 2.4.18-2ubuntu3.1, 2.4.23-2, 2.4.23-r1, 2.4.49-1.1, 2.4.7-1ubuntu4.13
apache2-devel
2.2.12-64.1, 2.4.16-12.1, 2.4.16-7.1
apache2-doc
2.2.12-64.1, 2.4.10-14.17.1, 2.4.16-12.1, 2.4.16-7.1
apache2-event
2.4.16-12.1
apache2-example-pages
2.2.12-64.1, 2.4.10-14.17.1, 2.4.16-12.1, 2.4.16-7.1
apache2-mod_fcgid
2.3.9-7.1
apache2-prefork
2.2.12-64.1, 2.4.10-14.17.1, 2.4.16-12.1, 2.4.16-7.1
apache2-utils
2.2.12-64.1, 2.4.10-14.17.1, 2.4.16-12.1, 2.4.16-7.1
apache2-worker
2.2.12-64.1, 2.4.10-14.17.1, 2.4.16-12.1, 2.4.16-7.1
System Management Homepage
7.5.5.0
httpd
0:2.2.15-54.el6_8, 0:2.2.3-92.el5_11, 0:2.4.6-40.el7_2.4, 2.2.15-54.0.1.el6_8, 2.2.3-92.0.1.el5_11, 2.2.31-1.8.amzn1, 2.4.6-40.0.1.el7_2.4
httpd-devel
2.2.15-54.0.1.el6_8, 2.2.3-92.0.1.el5_11, 2.2.31-1.8.amzn1, 2.4.6-40.0.1.el7_2.4
httpd-manual
2.2.15-54.0.1.el6_8, 2.2.3-92.0.1.el5_11, 2.2.31-1.8.amzn1, 2.4.6-40.0.1.el7_2.4
httpd-tools
2.2.15-54.0.1.el6_8, 2.2.31-1.8.amzn1, 2.4.6-40.0.1.el7_2.4
httpd22
0:2.2.26-56.ep6.el7
httpd24
0:2.4.6-62.ep7.el6, 0:2.4.6-62.ep7.el7, 2.4.23-1.65.amzn1
httpd24-devel
2.4.23-1.65.amzn1
httpd24-httpd
0:2.4.18-11.el6, 0:2.4.18-11.el7
httpd24-manual
2.4.23-1.65.amzn1
httpd24-tools
2.4.23-1.65.amzn1
jbcs-httpd24
0:1-3.jbcs.el6, 0:1-3.jbcs.el7
jbcs-httpd24-httpd
0:2.4.6-77.SP1.jbcs.el6, 0:2.4.6-77.SP1.jbcs.el7
jbcs-httpd24-openssl
1:1.0.2h-4.jbcs.el6, 1:1.0.2h-4.jbcs.el7
mod_cluster
0:1.2.13-1.Final_redhat_1.1.ep6.el6, 0:1.2.13-1.Final_redhat_1.1.ep6.el7
Timeline
Publicly disclosed
Jul 19, 2016
Last updated
Sep 23, 2026
Weakness Type
- CWE-20 Improper Input Validation
References
- advisoryopenSUSE-SU-2016:1824
- advisoryRHSA-2016:1624
- advisoryRHSA-2016:1625
- advisoryRHSA-2016:1648
- advisoryRHSA-2016:1649
FAQ
Common Questions.
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 c…
Affected: HTTP Server (Apache); System Management Homepage (Hp); Communications User Data Repository (Oracle), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including HTTP Server 2.2.31, apache2 2.2.12-64.1, apache2 2.2.22-13+deb7u7.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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