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CVE-2021-22991

F5 — F5 BIG-IP Traffic Management Microkernel Buffer Overflow

F5 · CWE-119 · in CISA KEV since 2022-01-18

KEV since 2022 · listed over a yearCISA KEVActively Exploited
77

EVRS 77 of 100 Urgent

Patch This Cycle

Rank 664 of 2,960 tracked

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Why it scores 77

Evidence available: 6 of 7 signals

Listed in the CISA KEV catalog, and an EPSS probability of 0.611.

  • CISA KEVApplied
  • RansomwareDid not apply
  • Vendor exploitationDid not apply
  • EPSSApplied
  • Microsoft Exploitability IndexNot applicable
  • Pre-patch disclosureNo data
  • KEV recencyDid not apply
  • CVSSApplied

The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data

Fix

Patch or fixed version identified

CISA required action

Fixed in

big-ip access policy manager: update to 12.1.5.3 or later | big-ip access policy manager: update to 13.1.3.6 or later | big-ip access policy manager: update to 14.1.4 or later | big-ip access policy manager: update to 15.1.2.1 or later | big-ip access policy manager: update to 16.0.1.1 or later | big-ip advanced firewall manager: update to 12.1.5.3 or later

Affected versions

  • big-ip access policy manager>= 12.1.0 < 12.1.5.3>= 13.1.0 < 13.1.3.6>= 14.1.0 < 14.1.4>= 15.1.0 < 15.1.2.1>= 16.0.0 < 16.0.1.1
  • big-ip advanced firewall manager>= 12.1.0 < 12.1.5.3>= 13.1.0 < 13.1.3.6>= 14.1.0 < 14.1.4>= 15.1.0 < 15.1.2.1>= 16.0.0 < 16.0.1.1
  • big-ip advanced web application firewall>= 12.1.0 < 12.1.5.3>= 13.1.0 < 13.1.3.6>= 14.1.0 < 14.1.4>= 15.1.0 < 15.1.2.1>= 16.0.0 < 16.0.1.1
  • big-ip analytics>= 12.1.0 < 12.1.5.3>= 13.1.0 < 13.1.3.6>= 14.1.0 < 14.1.4>= 15.1.0 < 15.1.2.1>= 16.0.0 < 16.0.1.1
  • big-ip application acceleration manager>= 12.1.0 < 12.1.5.3>= 13.1.0 < 13.1.3.6>= 14.1.0 < 14.1.4>= 15.1.0 < 15.1.2.1>= 16.0.0 < 16.0.1.1
  • big-ip application security manager>= 12.1.0 < 12.1.5.3>= 13.1.0 < 13.1.3.6>= 14.1.0 < 14.1.4>= 15.1.0 < 15.1.2.1>= 16.0.0 < 16.0.1.1
  • big-ip ddos hybrid defender>= 12.1.0 < 12.1.5.3>= 13.1.0 < 13.1.3.6>= 14.1.0 < 14.1.4>= 15.1.0 < 15.1.2.1>= 16.0.0 < 16.0.1.1
  • big-ip domain name system>= 12.1.0 < 12.1.5.3>= 13.1.0 < 13.1.3.6>= 14.1.0 < 14.1.4>= 15.1.0 < 15.1.2.1>= 16.0.0 < 16.0.1.1

+6 more affected products; see the full list at NVD.

Remediation

Apply updates per vendor instructions.

Fixed versions from NVD.

Evidence

Each value with its source
MeasureValueSource
CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. 9.8 NVD
FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. 0.611 (99.16th pctl) FIRST EPSS
Actively exploitedWhether a source of record has confirmed attacks using it in the wild. Confirmed CISA KEV
Ransomware campaign useWhether CISA has seen ransomware operators use it. Unknown or none CISA KEV
CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. 2022-02-01 · KEV since 2022 · listed over a year CISA KEV
Public exploit moduleA module existing is not the same as active exploitation. None known Metasploit
EUVD cross-referenceENISA's record: CVSS 9.8 (v3.1), assigned by f5. Listed ENISA EUVD

Description

NVD

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.

What CISA says to do