CVE-2021-22992Network attack vector

Service crash or code execution via backend response

Published Mar 31, 2021 · Updated Aug 3, 2024

Buffer overflow in F5 BIG-IP Advanced WAF/ASM 11.6.x through 16.0.x allows remote attackers to crash the service or execute code. The affected Login Page response-processing path fails to bound data copied from a backend HTTP response, overflowing a buffer. Exploitation requires an Advanced WAF or ASM virtual server whose policy has Login Page monitoring configured; a crash causes denial of service, while code execution can compromise the system.

CVSS severity9.8
Critical
EPSS probability72.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in F5 BIG-IP Advanced WAF/ASM 11.6.x through 16.0.x allows remote attackers to crash the service or execute code. The affected Login Page response-processing path fails to bound data copied from a backend HTTP response, overflowing a buffer. Exploitation requires an Advanced WAF or ASM virtual server whose policy has Login Page monitoring configured; a crash causes denial of service, while code execution can compromise the system.

The record

CVE
CVE-2021-22992
Published
Mar 31, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 31, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.3NISTAV:N/AC:M/Au:N/C:C/I:C/A:C
9.8NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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