CVE-2016-4979
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…
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 18.8%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.
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.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 18.80% probability · 97th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-284
- Affected
- apache/http server
- Source
- secalert@redhat.com
References
- http://httpd.apache.org/security/vulnerabilities_24.htmlPatch, Vendor Advisory
- http://packetstormsecurity.com/files/137771/Apache-2.4.20-X509-Authentication-Bypass.html
- http://seclists.org/fulldisclosure/2016/Jul/11
- http://www.apache.org/dist/httpd/CHANGES_2.4
- http://www.openwall.com/lists/oss-security/2016/07/05/5
- http://www.oracle.com/technetwork/security-advisory/cpuoct2016-2881722.html
- http://www.oracle.com/technetwork/topics/security/bulletinoct2016-3090566.html
- http://www.securityfocus.com/bid/91566
- http://www.securitytracker.com/id/1036225
- https://access.redhat.com/errata/RHSA-2016:1420
- https://github.com/apache/httpd/commit/2d0e4eff04ea963128a41faaef21f987272e05a2
- 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/r04e89e873d54116a0635ef2f7061c15acc5ed27ef7500997beb65d6f%40%3Ccvs.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r76142b8c5119df2178be7c2dba88fde552eedeec37ea993dfce68d1d%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/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/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://security.gentoo.org/glsa/201610-02
- https://security.netapp.com/advisory/ntap-20180601-0001/
- http://httpd.apache.org/security/vulnerabilities_24.htmlPatch, Vendor Advisory
- http://packetstormsecurity.com/files/137771/Apache-2.4.20-X509-Authentication-Bypass.html
- http://seclists.org/fulldisclosure/2016/Jul/11
- http://www.apache.org/dist/httpd/CHANGES_2.4
- http://www.openwall.com/lists/oss-security/2016/07/05/5
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.