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.
CVE-2021-22981
This medium-severity CVE scores 4.8 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 58% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 4.8
- EG Score
- 4.8(medium)
- EG Risk
- 26(Track)EG Risk 26/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity48% × 45%Exploitation1% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 43%
- KEV
- Not listed
Published
February 12, 2021
Last Modified
November 21, 2024
References (2)
- f5sirt@f5https://support.f5.com/csp/article/K09121542
- af854a3a-2127-422b-91ae-364da2661108https://support.f5.com/csp/article/K09121542
Data Freshness Timeline
(refreshed 7× in last 7d / 30× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 127 total refreshes for this CVE.
- 2026-08-20 22:52 UTCEPSS rescore
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Frequently asked(5)
What is CVE-2021-22981?
When was CVE-2021-22981 disclosed?
Is CVE-2021-22981 actively exploited?
What is the CVSS score of CVE-2021-22981?
How do I remediate CVE-2021-22981?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2021-22981
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