CVE-2021-23011 Denial of service in BIG-IP

High 7.5 Published 10 May 2021 Updated 3 Aug 2024

Attackers can cause resource exhaustion and system restarts in F5 BIG-IP devices by sending fragmented packets, 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-2021-23011?

CVE-2021-23011 is a high-severity denial of service vulnerability in F5 Big-Ip Access Policy Manager, published on 10 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

On versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.3, 14.1.x before 14.1.4, 13.1.x before 13.1.4, 12.1.x before 12.1.6, and 11.6.x before 11.6.5.3, when the BIG-IP system is buffering packet fragments for reassembly, the Traffic Management Microkernel (TMM) may consume an excessive amount of resources, eventually leading to a restart and failover event. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Weakness: CWE-400

Which versions are affected by CVE-2021-23011?

It affects 14 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 8 more.

How do I fix CVE-2021-23011?

No fix has been published for CVE-2021-23011 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-2021-23011 being exploited?

There is no known exploitation of CVE-2021-23011 in the wild and no public exploit code.

All F5 Big-Ip Access Policy Manager vulnerabilities

Sources

Also known as GHSA-65cc-qw75-2gw6.