CVE-2016-2161 Denial of service in Apache HTTP Server

What is CVE-2016-2161?

CVE-2016-2161 is a high-severity denial of service vulnerability in Apache Http Server, published on 27 Jul 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In Apache HTTP Server versions 2.4.0 to 2.4.23, malicious input to mod_auth_digest can cause the server to crash, and each instance continues to crash even for subsequently valid requests.

Weakness: CWE-20, CWE-823

Which versions are affected by CVE-2016-2161?

It affects 1 product.

Products include Apache Http Server.

How do I fix CVE-2016-2161?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2016-2161 being exploited?

There is no known exploitation of CVE-2016-2161 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-2016-2161, GHSA-3v6f-955w-932h, UBUNTU-CVE-2016-2161.