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CVE-2021-22981

MEDIUMCVSS 4.8/10EPSS 0.54%

Last modified

CVE-2021-22981 is a medium-severity vulnerability rated 4.8/10 on the CVSS scale. 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. EPSS estimates a 0.54% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
4.8/10

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

EPSS Probability
0.54%

41.1th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

VendorProductVersions
F5Big-Ip Access Policy Manager>= 11.6.1, <= 11.6.5
F5Big-Ip Access Policy Manager>= 12.1.0, <= 12.1.5
F5Big-Ip Advanced Firewall Manager>= 11.6.1, <= 11.6.5
F5Big-Ip Advanced Firewall Manager>= 12.1.0, <= 12.1.5
F5Big-Ip Advanced Web Application Firewall>= 11.6.1, <= 11.6.5
F5Big-Ip Advanced Web Application Firewall>= 12.1.0, <= 12.1.5
F5Big-Ip Analytics>= 11.6.1, <= 11.6.5
F5Big-Ip Analytics>= 12.1.0, <= 12.1.5
F5Big-Ip Application Acceleration Manager>= 11.6.1, <= 11.6.5
F5Big-Ip Application Acceleration Manager>= 12.1.0, <= 12.1.5
F5Big-Ip Application Security Manager>= 11.6.1, <= 11.6.5
F5Big-Ip Application Security Manager>= 12.1.0, <= 12.1.5
F5Big-Ip Ddos Hybrid Defender>= 11.6.1, <= 11.6.5
F5Big-Ip Ddos Hybrid Defender>= 12.1.0, <= 12.1.5
F5Big-Ip Domain Name System>= 11.6.1, <= 11.6.5
F5Big-Ip Domain Name System>= 12.1.0, <= 12.1.5
F5Big-Ip Fraud Protection Service>= 11.6.1, <= 11.6.5
F5Big-Ip Fraud Protection Service>= 12.1.0, <= 12.1.5
F5Big-Ip Global Traffic Manager>= 11.6.1, <= 11.6.5
F5Big-Ip Global Traffic Manager>= 12.1.0, <= 12.1.5
F5Big-Ip Link Controller>= 11.6.1, <= 11.6.5
F5Big-Ip Link Controller>= 12.1.0, <= 12.1.5
F5Big-Ip Local Traffic Manager>= 11.6.1, <= 11.6.5
F5Big-Ip Local Traffic Manager>= 12.1.0, <= 12.1.5
F5Big-Ip Policy Enforcement Manager>= 11.6.1, <= 11.6.5
F5Big-Ip Policy Enforcement Manager>= 12.1.0, <= 12.1.5
F5Big-Ip Ssl Orchestrator>= 11.6.1, <= 11.6.5
F5Big-Ip Ssl Orchestrator>= 12.1.0, <= 12.1.5

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is 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 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.
How severe is CVE-2021-22981?
CVE-2021-22981 has a CVSS score of 4.8/10 (MEDIUM severity). The EPSS model estimates a 0.54% probability of exploitation in the next 30 days.
How do I fix CVE-2021-22981?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-22981?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST