CVE-2021-22991

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2022-01-18. Federal remediation due 2022-02-01.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

62.42% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 99.1% of scored records. A rank, not a probability.

NVD base score

9.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-03-31 17:23Z5 YR AGO

Last updated

2025-10-21 23:25Z1 YR AGO

Reserved

2021-01-06

Assigning CNA

f5

Record state

PUBLISHED

Severity

Critical (CVSS 9.8)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weaknesses

• CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferClass

Data version

5.1

Document digest

d15580b6275528daa2791f96f514ef5d14e221e2c906543e46b1614fe0b4793f

• support.f5.comhttps://support.f5.com/csp/article/K56715231x_refsource_MISC
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22991government-resource