CVE-2016-4979 Auth bypass in n/a

What is CVE-2016-4979?

CVE-2016-4979 is a high-severity authentication bypass vulnerability in Apache Http Server, published on 6 Jul 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-284

Which versions are affected by CVE-2016-4979?

It affects 1 product.

Products include Apache Http Server.

How do I fix CVE-2016-4979?

Upgrade to a fixed version.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2016-4979 being exploited?

There is no known exploitation of CVE-2016-4979 in the wild and no public exploit code.

Other vulnerabilities in Apache Http Server

• CVE-2021-42013 Apache HTTP Server Path Traversal Exploited Critical 9.8
• CVE-2024-38475 Apache HTTP Server Improper Escaping of Output Exploited Critical 9.1
• CVE-2021-40438 Apache HTTP Server-Side Request Forgery (SSRF) Exploited Critical 9.0
• CVE-2019-0211 Apache HTTP Server Privilege Escalation Exploited High 7.8
• CVE-2021-41773 Apache HTTP Server Path Traversal Exploited High 7.5

All Apache Http Server vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2016-4979, GHSA-r48c-7gpg-9q4x.