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CVE-2021-22991

Improper Restriction of Memory Buffer — is CVE-2021-22991real, exploitable, or a false positive? Here's the community ground truth.

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Critical · CVSS 9.8EPSS 61.1%CISA KEVCWE-119 · Improper Restriction of Memory Buffer

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

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.

References

NVD MITRE CVE.org CISA KEV

Published

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Community ground truth

Community verdict

3 verdicts
Not a real issue

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Community real-world severity: Critical (Critical 3) — CVSS base score 9.8

In line with its CVSS base score.

Field notes & remediation

Verdicts are the quick signal — notes are the evidence and fixes behind them.

  • 0
    Field note · Mara OkonkwoCurated

    F5 BIG-IP Traffic Management Microkernel Buffer Overflow — The Traffic Management Microkernel of BIG-IP ASM Risk Engine has a buffer overflow vulnerability, leading to a bypassing of URL-based access controls. Listed in the CISA KEV catalog (added 2022-01-18) — confirmed exploited in the wild, not theoretical. FIRST EPSS puts the chance of exploitation in the next 30 days at ~61%. Treat it as real and prioritize remediation over triage.

  • 0
    Remediation · Yuki TanakaCurated

    Required action for F5 BIG-IP Traffic Management Microkernel: Apply updates per vendor instructions. CISA set a federal remediation due date of 2022-02-01. After patching, verify the vulnerable path is no longer reachable before closing the finding.

Related CVEs

Same weakness — CWE-119 · Improper Restriction of Memory Buffer.