CVE-2021-22991

mediumpriority · act · 90OT risk · criticalKEV · exploitedEPSS 0.624 · 99 %ileEURUUS

grimoire priorityP0 · Act now

Exploitable?

Yes · in the wild

CISA KEV

Likely / severe?

62.4% (99th) EPSS

CVSS 6.8 · medium

Is it mine?

141 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · fstec_bdu

added 2022-01-18remediate by 2022-02-01

required action Apply updates per vendor instructions.

EPSS · scored 2026-10-27

F5 BIG-IP Traffic Management Microkernel Buffer Overflow

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.

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 6.8–9.8

v2.06.8mediumAV:N/AC:M/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 6.4

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v3.19criticalAV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondaryexploitability 3.9 · impact 5.9

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Hsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: active · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-119USprimaryCWE-79US

affected products (141)

Products and version ranges known to be affected.

n/a BIG-IP≤ 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 12.1.5.3enisa_euvdEU
F5 Networks, Inc. BIG-IP Access Policy Manager12.1.0 → 12.1.5.3fstec_bduRU
F5 Networks, Inc. BIG-IP Access Policy Manager13.1.0 → 13.1.3.6fstec_bduRU
F5 Networks, Inc. BIG-IP Access Policy Manager14.1.0 → 14.1.4fstec_bduRU
F5 Networks, Inc. BIG-IP Access Policy Manager15.1.0 → 15.1.2.1fstec_bduRU
F5 Networks, Inc. BIG-IP Access Policy Manager16.0.0 → 16.0.1.1fstec_bduRU
F5 Networks, Inc. BIG-IP Advanced Firewall Manager12.1.0 → 12.1.5.3fstec_bduRU
F5 Networks, Inc. BIG-IP Advanced Firewall Manager13.1.0 → 13.1.3.6fstec_bduRU
F5 Networks, Inc. BIG-IP Advanced Firewall Manager14.1.0 → 14.1.4fstec_bduRU
F5 Networks, Inc. BIG-IP Advanced Firewall Manager15.1.0 → 15.1.2.1fstec_bduRU
F5 Networks, Inc. BIG-IP Advanced Firewall Manager16.0.0 → 16.0.1.1fstec_bduRU
F5 Networks, Inc. BIG-IP Advanced Web Application Firewall12.1.0 → 12.1.5.3fstec_bduRU
F5 Networks, Inc. BIG-IP Advanced Web Application Firewall13.1.0 → 13.1.3.6fstec_bduRU
F5 Networks, Inc. BIG-IP Advanced Web Application Firewall14.1.0 → 14.1.4fstec_bduRU
F5 Networks, Inc. BIG-IP Advanced Web Application Firewall15.1.0 → 15.1.2.1fstec_bduRU
F5 Networks, Inc. BIG-IP Advanced Web Application Firewall16.0.0 → 16.0.1.1fstec_bduRU
F5 Networks, Inc. BIG-IP Analytics12.1.0 → 12.1.5.3fstec_bduRU
F5 Networks, Inc. BIG-IP Analytics13.1.0 → 13.1.3.6fstec_bduRU
F5 Networks, Inc. BIG-IP Analytics14.1.0 → 14.1.4fstec_bduRU
F5 Networks, Inc. BIG-IP Analytics15.1.0 → 15.1.2.1fstec_bduRU

showing 20 of 141

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu NVD CVE.org MITRE

published 2021-03-31modified 2026-06-17

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+21023 more

references (8)

External citations — patches, advisories, analysis.

scry

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