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Vulnerability record · CVE-2016-2161 · published 27 July 2017

CVE-2016-2161: Apache http server improper input validation vulnerability

Apache · Http Server

In Apache HTTP Server versions 2.4.0 to 2.4.23, malicious input to mod_auth_digest can cause the server to crash, and each instance continues to crash even for subsequently valid requests.

7.5 CVSS 3.0 High EPSS 21% · top 2.5% CWE-823 · CWE-823CWE-20 · Improper input validation
7.5CVSS 3.0 base score, v2 5.0
21%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
54References
17 Jun 2026Last modified by NVD

Description

In Apache HTTP Server versions 2.4.0 to 2.4.23, malicious input to mod_auth_digest can cause the server to crash, and each instance continues to crash even for subsequently valid requests.

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://rhn.redhat.com/errata/RHSA-2017-1415.html
http://www.debian.org/security/2017/dsa-3796
http://www.securityfocus.com/bid/95076 Third Party AdvisoryVDB Entry
http://www.securitytracker.com/id/1037508 Third Party AdvisoryVDB Entry
https://access.redhat.com/errata/RHSA-2017:0906
https://access.redhat.com/errata/RHSA-2017:1161
https://access.redhat.com/errata/RHSA-2017:1413
https://access.redhat.com/errata/RHSA-2017:1414
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03725en_us Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2016-2161 Vendor Advisory
https://lists.apache.org/thread.html/56c2e7cc9deb1c12a843d0dc251ea7fd3e7e80293cde02fcd65286ba%40%3Ccvs.httpd.apache.org%
https://lists.apache.org/thread.html/84a3714f0878781f6ed84473d1a503d2cc382277e100450209231830%40%3Ccvs.httpd.apache.org%
https://lists.apache.org/thread.html/r04e89e873d54116a0635ef2f7061c15acc5ed27ef7500997beb65d6f%40%3Ccvs.httpd.apache.org
https://lists.apache.org/thread.html/r76142b8c5119df2178be7c2dba88fde552eedeec37ea993dfce68d1d%40%3Ccvs.httpd.apache.org
https://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org
https://lists.apache.org/thread.html/rb14daf9cc4e28d18cdc15d6a6ca74e565672fabf7ad89541071d008b%40%3Ccvs.httpd.apache.org
https://lists.apache.org/thread.html/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%40%3Ccvs.httpd.apache.org
https://lists.apache.org/thread.html/rcc44594d4d6579b90deccd4536b5d31f099ef563df39b094be286b9e%40%3Ccvs.httpd.apache.org
https://lists.apache.org/thread.html/rd18c3c43602e66f9cdcf09f1de233804975b9572b0456cc582390b6f%40%3Ccvs.httpd.apache.org
https://lists.apache.org/thread.html/rd336919f655b7ff309385e34a143e41c503e133da80414485b3abcc9%40%3Ccvs.httpd.apache.org
https://lists.apache.org/thread.html/re1e3a24664d35bcd0a0e793e0b5fc6ca6c107f99a1b2c545c5d4b467%40%3Ccvs.httpd.apache.org
https://lists.apache.org/thread.html/re3d27b6250aa8548b8845d314bb8a350b3df326cacbbfdfe4d455234%40%3Ccvs.httpd.apache.org
https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org
https://security.gentoo.org/glsa/201701-36 Third Party Advisory
https://security.netapp.com/advisory/ntap-20180423-0001/
https://support.apple.com/HT208221
https://www.tenable.com/security/tns-2017-04
http://rhn.redhat.com/errata/RHSA-2017-1415.html
http://www.debian.org/security/2017/dsa-3796
http://www.securityfocus.com/bid/95076 Third Party AdvisoryVDB Entry
http://www.securitytracker.com/id/1037508 Third Party AdvisoryVDB Entry
https://access.redhat.com/errata/RHSA-2017:0906
https://access.redhat.com/errata/RHSA-2017:1161
https://access.redhat.com/errata/RHSA-2017:1413
https://access.redhat.com/errata/RHSA-2017:1414
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03725en_us Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2016-2161 Vendor Advisory
https://lists.apache.org/thread.html/56c2e7cc9deb1c12a843d0dc251ea7fd3e7e80293cde02fcd65286ba%40%3Ccvs.httpd.apache.org%
https://lists.apache.org/thread.html/84a3714f0878781f6ed84473d1a503d2cc382277e100450209231830%40%3Ccvs.httpd.apache.org%
https://lists.apache.org/thread.html/r04e89e873d54116a0635ef2f7061c15acc5ed27ef7500997beb65d6f%40%3Ccvs.httpd.apache.org

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Source: NIST National Vulnerability Database (record CVE-2016-2161), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.