CVE-2021-22991: F5 BIG-IP Traffic Management Microkernel Buffer Overflow

CVE-2021-22991 · Severity: critical · CVSS 9.8 · Exploited in the wild · Published 2022-01-18

A buffer overflow vulnerability exists in the F5 BIG-IP Traffic Management Microkernel (TMM) URI normalization process when handling undisclosed requests to a virtual server. This flaw can lead to a denial-of-service (DoS) attack, bypass of URL-based access controls, or potentially remote code execution (RCE).

Vendors: F5.

Quick answers

Is CVE-2021-22991 exploited in the wild?
Yes. CVE-2021-22991 is known to be exploited in the wild, first recorded on 18 January 2022. Treat it as urgent.
How severe is CVE-2021-22991?
Critical severity, with a CVSS score of 9.8, published 18 January 2022.
Which products and versions are affected?
F5 BIG-IP ASM Risk Engine 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, 12.1.x before 12.1.5.3.
Is there a fix for CVE-2021-22991?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2021-22991 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2021-22991?
Check whether you run F5 BIG-IP Traffic Management Microkernel. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Affected products

  • F5 BIG-IP ASM Risk Engine 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, 12.1.x before 12.1.5.3

Timeline

  • 2021-03-31: disclosed: NVD Published Date
  • 2022-01-18: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
  • 2022-01-18: exploited: Reported as exploited in the wild in advisory metadata

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