CVE-2021-22991 F5 BIG-IP Traffic Management Microkernel Buffer Overflow
Buffer overflow in TMM URI normalization allows DoS, potential RCE, or access control bypass on BIG-IP devices.
- Exploited in the wild
- Since 18 Jan 2022
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-22991?
CVE-2021-22991 is a critical memory corruption vulnerability in F5 Big-Ip Access Policy Manager, published on 31 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, and 12.1.x before 12.1.5.3, undisclosed requests to a virtual server may be incorrectly handled by the Traffic Management Microkernel (TMM) URI normalization, which may trigger a buffer overflow, resulting in a DoS attack. In certain situations, it may theoretically allow bypass of URL based access control or remote code execution (RCE). Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.
Weakness: CWE-119
Which versions are affected by CVE-2021-22991?
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-2021-22991?
No fix has been published for CVE-2021-22991 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 1 Feb 2022.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2021-22991 being exploited?
Yes. Attackers have exploited CVE-2021-22991 in the wild since at least 18 Jan 2022.
Other vulnerabilities in F5 Big-Ip Access Policy Manager
- CVE-2023-46747 F5 BIG-IP Configuration Utility Authentication Bypass
- CVE-2022-1388 F5 BIG-IP Missing Authentication
- CVE-2021-22986 F5 BIG-IP and BIG-IQ Centralized Management iControl REST Remote Code Execution
- CVE-2020-5902 F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution
- CVE-2026-94127 F5 BIG-IP APM Heap-based Buffer Overflow
Sources
Also known as GHSA-6w8r-pjm3-q7x7.