CVE-2016-4979

high Apache
CVSS v3 Base Score
7.5
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score
17.4%
Exploitation probability in 30 days
Top 5% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
High
Availability
None
Published: July 6, 2016 (3600 days ago)
Last Modified: May 6, 2026
Vendor: Apache
Source: NVD

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.

CWE

CWE-284

Affected Products

apache http server

References

🔗 httpd.apache.org 🔗 packetstormsecurity.com 🔗 seclists.org 🔗 www.apache.org 🔗 www.openwall.com