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CVE record · CVE-2021-22991

Buffer overflow in BIG-IP

CVSS 9.8 CriticalCriticalIn CISA KEVEPSS 0.62 · 99th percentile

Critical, because:

  • In CISA’s KEV catalogue since 18 Jan 2022: it is known to be exploited.
  • CVSS score 9.8: 9.0 or more.
  • CVSS score 9.8 (7.0 or more) and EPSS 0.62 (0.1 or more): a high score and a real chance of exploitation in the next 30 days.

How we decide what’s critical

Published by the CVE Program (CNA: f5) at 31 Mar 2021, 17:23 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
VendorProductVersions
Not given BIG-IP
  • affected 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
Identifiers
CVE-2021-22991
CNA
f5
Weakness (CWE)
CWE-119
Tags
Published
31 Mar 2021
Updated
21 Oct 2025

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

ScoreRatingCVSSVectorSource
9.8 Critical 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H ADP (CISA-ADP)
  • CISA KEV Listed since 18 Jan 2022: known to be exploited.
  • EPSS 0.62, the 99th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 31 Mar 2021. New records show when each source confirmed them.

Sources

References from the CNA

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.