CVE-2023-40534 BIG-IP HTTP/2 vulnerability

High 7.5 Published 10 Oct 2023 Updated 19 Sep 2024

Attackers can cause TMM termination on BIG-IP devices when specific HTTP/2 and iRule configurations are enabled, leading to service disruption.

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-2023-40534?

CVE-2023-40534 is a high-severity denial of service vulnerability in F5 Big-Ip Access Policy Manager, published on 10 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

When a client-side HTTP/2 profile and the HTTP MRF Router option are enabled for a virtual server, and an iRule using the HTTP_REQUEST event or Local Traffic Policy are associated with the virtual server, undisclosed requests can cause TMM to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Weakness: CWE-401

Which versions are affected by CVE-2023-40534?

It affects 20 products.

Products include F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager, F5 Big-Ip Advanced Web Application Firewall, F5 Big-Ip Analytics, F5 Big-Ip Application Acceleration Manager, F5 Big-Ip Application Security Manager and 14 more.

How do I fix CVE-2023-40534?

No fix has been published for CVE-2023-40534 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-2023-40534 being exploited?

There is no known exploitation of CVE-2023-40534 in the wild and no public exploit code.

All F5 Big-Ip Access Policy Manager vulnerabilities

Sources

Also known as GHSA-w99g-74qg-jcgf.