CVE-2021-23044Network attack vector

Service interruption via QAT-triggered TMM termination

Published Sep 14, 2021 · Updated Aug 3, 2024

Improper input validation in affected F5 BIG-IP releases allows remote attackers to interrupt service via undisclosed traffic. When Intel QAT compression is in use on affected hardware or VE platforms, that traffic makes TMM terminate; F5 has not disclosed its exact form. The vulnerable path is limited to deployments using the QAT compression driver, and TMM termination disrupts application traffic.

CVSS severity7.5
High
EPSS probability0.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper input validation in affected F5 BIG-IP releases allows remote attackers to interrupt service via undisclosed traffic. When Intel QAT compression is in use on affected hardware or VE platforms, that traffic makes TMM terminate; F5 has not disclosed its exact form. The vulnerable path is limited to deployments using the QAT compression driver, and TMM termination disrupts application traffic.

The record

CVE
CVE-2021-23044
Published
Sep 14, 2021
Updated
Aug 3, 2024
Vendor
F5 Networks
Product
BIG-IP
Classifications
CWE-20, T1498
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 14, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=16.x before 16.1.0, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.2, 13.1.x before 13.1.4.1, and all versions of 12.1.x and 11.6.x

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

F5 Networks · BIG-IPversion=16.x before 16.1.0, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.2, 13.1.x before 13.1.4.1, and all versions of 12.1.x and 11.6.x

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1498Network Denial of Service

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo