{"cve":"CVE-2021-22981","nvd":{"published":"2021-02-12T18:15:12.797","modified":"2026-06-17T03:38:08.890","status":"Modified","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","score":4.8},"cwes":[],"references":["https://support.f5.com/csp/article/K09121542","https://support.f5.com/csp/article/K09121542"],"products":["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":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-22981","score":0.00555,"percentile":0.46357,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}