CVE-2016-5387

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.

Published: 2016-07-19 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-5387 is rated Moderate Risk (61.7/100): CVSS High severity, with high exploitation likelihood (EPSS 51.56%, 98th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-5387

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-01 60.28% 51.56% -8.72%
2 2026-04-04 41.96% 60.28% +18.32%
3 2026-03-30 — 41.96% —

Full EPSS history (51 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-5387

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2016-5387

OS Trackers for CVE-2016-5387

vendor priority summary link
debian not yet assigned CVE-2016-5387 not yet assigned priority: Debian including 1 source packages (apache2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-5387
gentoo normal CVE-2016-5387: 1 GLSA(s) (201701-36), 1 atom(s) (www-servers/apache); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-5387
redhat high — https://access.redhat.com/security/cve/CVE-2016-5387
suse medium — https://www.suse.com/security/cve/CVE-2016-5387/
ubuntu medium CVE-2016-5387 medium priority: Ubuntu including 1 source packages (apache2), 5 status rows across 5 suites (precise, trusty, upstream, wily, xenial): released 4, needs-triage 1. https://ubuntu.com/security/CVE-2016-5387

Affected software / configurations for CVE-2016-5387

Vendor Product Version Raw CPE
apache http_server >= 2.2.0, <= 2.2.31 cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
apache http_server >= 2.4.1, <= 2.4.23 cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
hp system_management_homepage <= 7.5.5.0 cpe:2.3:a:hp:system_management_homepage:*:*:*:*:*:*:*:*
oracle communications_user_data_repository >= 10.0.0, <= 12.4 cpe:2.3:a:oracle:communications_user_data_repository:*:*:*:*:*:*:*:*
oracle enterprise_manager_ops_center 12.2.2 cpe:2.3:a:oracle:enterprise_manager_ops_center:12.2.2:*:*:*:*:*:*:*
oracle enterprise_manager_ops_center 12.3.2 cpe:2.3:a:oracle:enterprise_manager_ops_center:12.3.2:*:*:*:*:*:*:*
oracle linux 5 cpe:2.3:o:oracle:linux:5:-:*:*:*:*:*:*
oracle linux 6 cpe:2.3:o:oracle:linux:6:-:*:*:*:*:*:*
oracle linux 7 cpe:2.3:o:oracle:linux:7:-:*:*:*:*:*:*
oracle solaris 11.3 cpe:2.3:o:oracle:solaris:11.3:*:*:*:*:*:*:*
fedoraproject fedora 23 cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:*
fedoraproject fedora 24 cpe:2.3:o:fedoraproject:fedora:24:*:*:*:*:*:*:*
redhat jboss_web_server 2.1.0 cpe:2.3:a:redhat:jboss_web_server:2.1.0:*:*:*:*:*:*:*
redhat jboss_enterprise_web_server 2.0.0 cpe:2.3:a:redhat:jboss_enterprise_web_server:2.0.0:*:*:*:*:*:*:*
redhat jboss_enterprise_web_server 3.0.0 cpe:2.3:a:redhat:jboss_enterprise_web_server:3.0.0:*:*:*:*:*:*:*
redhat jboss_core_services 1.0 cpe:2.3:a:redhat:jboss_core_services:1.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 6.0 cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 7.0 cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_eus 7.2 cpe:2.3:o:redhat:enterprise_linux_eus:7.2:*:*:*:*:*:*:*
redhat enterprise_linux_eus 7.3 cpe:2.3:o:redhat:enterprise_linux_eus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_eus 7.4 cpe:2.3:o:redhat:enterprise_linux_eus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_eus 7.5 cpe:2.3:o:redhat:enterprise_linux_eus:7.5:*:*:*:*:*:*:*
redhat enterprise_linux_eus 7.6 cpe:2.3:o:redhat:enterprise_linux_eus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_eus 7.7 cpe:2.3:o:redhat:enterprise_linux_eus:7.7:*:*:*:*:*:*:*
redhat enterprise_linux_server 6.0 cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.2 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.4 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.7 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.2 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.7 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.7:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 6.0 cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 7.0 cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:-:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 15.10 cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
opensuse leap 42.1 cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*
opensuse opensuse 13.2 cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*

References for CVE-2016-5387

URL Tags
http://lists.opensuse.org/opensuse-updates/2016-07/msg00059.html Mailing List Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-1624.html Broken Link Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-1625.html Broken Link Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-1648.html Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-1649.html Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-1650.html Broken Link Third Party Advisory
http://www.debian.org/security/2016/dsa-3623 Third Party Advisory
http://www.kb.cert.org/vuls/id/797896 Third Party Advisory US Government Resource
http://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html Patch Third Party Advisory
http://www.oracle.com/technetwork/security-advisory/cpujul2017-3236622.html Patch Third Party Advisory
http://www.oracle.com/technetwork/topics/security/bulletinoct2016-3090566.html Third Party Advisory
http://www.oracle.com/technetwork/topics/security/linuxbulletinjul2016-3090544.html Third Party Advisory
http://www.securityfocus.com/bid/91816 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1036330 Broken Link Third Party Advisory VDB Entry
http://www.ubuntu.com/usn/USN-3038-1 Third Party Advisory
https://access.redhat.com/errata/RHSA-2016:1420 Third Party Advisory
https://access.redhat.com/errata/RHSA-2016:1421 Third Party Advisory
https://access.redhat.com/errata/RHSA-2016:1422 Third Party Advisory
https://access.redhat.com/errata/RHSA-2016:1635 Third Party Advisory
https://access.redhat.com/errata/RHSA-2016:1636 Third Party Advisory
https://access.redhat.com/errata/RHSA-2016:1851 Third Party Advisory
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03770en_us Third Party Advisory
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05320149 Third Party Advisory
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05390722 Third Party Advisory
https://httpoxy.org/ Third Party Advisory
https://lists.apache.org/thread.html/56c2e7cc9deb1c12a843d0dc251ea7fd3e7e80293cde02fcd65286ba%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/84a3714f0878781f6ed84473d1a503d2cc382277e100450209231830%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/8d63cb8e9100f28a99429b4328e4e7cebce861d5772ac9863ba2ae6f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/f7f95ac1cd9895db2714fa3ebaa0b94d0c6df360f742a40951384a53%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r04e89e873d54116a0635ef2f7061c15acc5ed27ef7500997beb65d6f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r476d175be0aaf4a17680ef98c5153b4d336eaef76fb2224cc94c463a%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r57608dc51b79102f3952ae06f54d5277b649c86d6533dcd6a7d201f7%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r75cbe9ea3e2114e4271bbeca7aff96117b50c1b6eb7c4772b0337c1f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r9ea3538f229874c80a10af473856a81fbf5f694cd7f471cc679ba70b%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rad01d817195e6cc871cb1d73b207ca326379a20a6e7f30febaf56d24%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rb14daf9cc4e28d18cdc15d6a6ca74e565672fabf7ad89541071d008b%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rcc44594d4d6579b90deccd4536b5d31f099ef563df39b094be286b9e%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rd18c3c43602e66f9cdcf09f1de233804975b9572b0456cc582390b6f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rd336919f655b7ff309385e34a143e41c503e133da80414485b3abcc9%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rdca61ae990660bacb682295f2a09d34612b7bb5f457577fe17f4d064%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/re1e3a24664d35bcd0a0e793e0b5fc6ca6c107f99a1b2c545c5d4b467%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/re3d27b6250aa8548b8845d314bb8a350b3df326cacbbfdfe4d455234%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rfbaf647d52c1cb843e726a0933f156366a806cead84fbd430951591b%40%3Ccvs.httpd.apache.org%3E
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6WCTE7443AYZ4EGELWLVNANA2WJCJIYI/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NEKZAB7MTWVSMORHTEMCQNFFMIHCYF76/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QPQAPWQA774JPDRV4UIB2SZAX6D3UZCV/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TGNHXJJSWDXAOEYH5TMXDPQVJMQQJOAZ/
https://security.gentoo.org/glsa/201701-36 Third Party Advisory
https://support.apple.com/HT208221 Third Party Advisory
https://www.apache.org/security/asf-httpoxy-response.txt Vendor Advisory
https://www.tenable.com/security/tns-2017-04 Third Party Advisory
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