CVE-2021-23033 Denial of service in BIG-IP Advanced WAF and BIG-IP ASM

High 7.5 Published 14 Sep 2021 Updated 3 Aug 2024

Attackers can cause a denial of service by sending undisclosed requests to BIG-IP WAF/ASM when a WebSocket profile is configured.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-23033?

CVE-2021-23033 is a high-severity denial of service vulnerability in F5 Big-Ip Advanced Web Application Firewall, published on 14 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

On BIG-IP Advanced WAF and BIG-IP ASM version 16.x before 16.1.0x, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.3, 13.1.x before 13.1.4.1, and all versions of 12.1.x, when a WebSocket profile is configured on a virtual server, undisclosed requests can cause bd to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Weakness: CWE-20

Which versions are affected by CVE-2021-23033?

It affects 2 products.

Products include F5 Big-Ip Advanced Web Application Firewall, F5 Big-Ip Application Security Manager.

How do I fix CVE-2021-23033?

No fix has been published for CVE-2021-23033 yet. Limit exposure of the affected software until one is available.

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-2021-23033 being exploited?

There is no known exploitation of CVE-2021-23033 in the wild and no public exploit code.

All F5 Big-Ip Advanced Web Application Firewall vulnerabilities

Sources

Also known as GHSA-g6q2-6x3v-j3cw.