CVE-2021-23035 Denial of service in BIG-IP

High 7.5 Published 14 Sep 2021 Updated 3 Aug 2024

Attackers can cause a denial of service by sending specific packet sequences to a BIG-IP virtual server with an HTTP profile 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-2021-23035?

CVE-2021-23035 is a high-severity denial of service vulnerability in F5 Big-Ip Access Policy Manager, 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 14.1.x before 14.1.4.4, when an HTTP profile is configured on a virtual server, after a specific sequence of packets, chunked responses can cause the Traffic Management Microkernel (TMM) 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-2021-23035?

It affects 11 products.

Products include F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager, F5 Big-Ip Analytics, F5 Big-Ip Application Acceleration Manager, F5 Big-Ip Application Security Manager, F5 Big-Ip Domain Name System and 5 more.

How do I fix CVE-2021-23035?

No fix has been published for CVE-2021-23035 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-2021-23035 being exploited?

There is no known exploitation of CVE-2021-23035 in the wild and no public exploit code.

All F5 Big-Ip Access Policy Manager vulnerabilities

Sources

Also known as GHSA-498v-8jr7-2hv8.