CVE-2016-4979

HIGH

Apache HTTP Server 2.4.18-2.4.20 - Authentication Bypass via HTTP/2 Request Handling

Title source: llm
STIX 2.1

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.

References (25)

Core 25
Core References
Vendor Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2016:1420
Patch, Vendor Advisory x_refsource_confirm
http://httpd.apache.org/security/vulnerabilities_24.html
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/201610-02
Various Sources x_refsource_confirm
http://www.apache.org/dist/httpd/CHANGES_2.4
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/91566
Third Party Advisory, VDB Entry vdb-entry x_refsource_sectrack
http://www.securitytracker.com/id/1036225
Mailing List mailing-list x_refsource_mlist
http://www.openwall.com/lists/oss-security/2016/07/05/5
Vendor Advisory x_refsource_confirm
https://security.netapp.com/advisory/ntap-20180601-0001/
Mailing List mailing-list x_refsource_fulldisc
http://seclists.org/fulldisclosure/2016/Jul/11

Scores

CVSS v3 7.5
EPSS 0.1736
EPSS Percentile 95.1%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Details

CWE
CWE-284
Status published
Products (3)
apache/http_server 2.4.18
apache/http_server 2.4.19
apache/http_server 2.4.20
Published Jul 06, 2016
Tracked Since Feb 18, 2026