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Medium4.8F5

Medium [CVE-2021-22981] On all versions of BIG-IP 12.1.x and 11.6.x, the original TLS protocol includes a weakness in the master secret negotiation that…

This medium-severity F5 advisory covers CVE-2021-22981 affecting BIG-IP.

CVE-2021-22981 Published Feb 12, 2021Updated by vendor Jun 17, 2026
Related products & platforms
F5BIG-IP
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Summary

On all versions of BIG-IP 12.1.x and 11.6.x, the original TLS protocol includes a weakness in the master secret negotiation that is mitigated by the Extended Master Secret (EMS) extension defined in RFC 7627. TLS connections that do not use EMS are vulnerable to man-in-the-middle attacks during renegotiation.

Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.

Affected versions
  • all versions

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

Fixed versions

No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

Mitigation

The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

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