CVE-2016-4979

Description

The Apache HTTP Server 2.4.18 through 2.4.20, when mod_http2 and mod_ssl are enabled, does not properly recognize the "SSLVerifyClient require" directive for HTTP/2 request authorization, which allows remote attackers to bypass intended access restrictions by leveraging the ability to send multiple requests over a single connection and aborting a renegotiation.

Category

7.5
CVSS
Severity: High
CVSS 3.0 •
CVSS 2.0 •
EPSS 44.54% Top 5%
Vendor Advisory redhat.com Vendor Advisory gentoo.org Vendor Advisory apache.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://access.redhat.com/errata/RHSA-2016:1420 vendor advisory
http://httpd.apache.org/security/vulnerabilities_24.html patch vendor advisory
https://security.gentoo.org/glsa/201610-02 vendor advisory
http://seclists.org/fulldisclosure/2016/Jul/11 mailing list
http://www.oracle.com/technetwork/security-advisory/cpuoct2016-2881722.html
http://www.apache.org/dist/httpd/CHANGES_2.4
http://www.securityfocus.com/bid/91566 vdb entry
http://www.oracle.com/technetwork/topics/security/bulletinoct2016-3090566.html
http://www.securitytracker.com/id/1036225 vdb entry
http://www.openwall.com/lists/oss-security/2016/07/05/5 mailing list
https://github.com/apache/httpd/commit/2d0e4eff04ea963128a41faaef21f987272e05a2
http://packetstormsecurity.com/files/137771/Apache-2.4.20-X509-Authentication-Bypass.html
https://security.netapp.com/advisory/ntap-20180601-0001/
https://lists.apache.org/thread.html/56c2e7cc9deb1c12a843d0dc251ea7fd3e7e80293cde02fcd65286ba%40%3Ccvs.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/84a3714f0878781f6ed84473d1a503d2cc382277e100450209231830%40%3Ccvs.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/rd18c3c43602e66f9cdcf09f1de233804975b9572b0456cc582390b6f%40%3Ccvs.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/re3d27b6250aa8548b8845d314bb8a350b3df326cacbbfdfe4d455234%40%3Ccvs.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%40%3Ccvs.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/re1e3a24664d35bcd0a0e793e0b5fc6ca6c107f99a1b2c545c5d4b467%40%3Ccvs.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/r04e89e873d54116a0635ef2f7061c15acc5ed27ef7500997beb65d6f%40%3Ccvs.httpd.apache.org%3E mailing list
https://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3E mailing list
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Frequently Asked Questions

What is the severity of CVE-2016-4979?
CVE-2016-4979 has been scored as a high severity vulnerability.
How to fix CVE-2016-4979?
To fix CVE-2016-4979, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2016-4979 being actively exploited in the wild?
It is possible that CVE-2016-4979 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~45% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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