SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

MEDIUM 4.8EPSS 0.56%

Does this matter?

Lower severity and a low EPSS score (0.56%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
4.8 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS
0.56% probability · 45th percentile
CISA KEV
Not listed
Affected
f5/big-ip access policy manager · f5/big-ip advanced firewall manager · f5/big-ip advanced web application firewall · f5/big-ip analytics · f5/big-ip application acceleration manager · f5/big-ip application security manager · f5/big-ip ddos hybrid defender · f5/big-ip domain name system · f5/big-ip fraud protection service · f5/big-ip global traffic manager · f5/big-ip link controller · f5/big-ip local traffic manager · f5/big-ip policy enforcement manager · f5/big-ip ssl orchestrator
Source
f5sirt@f5.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.