How severe is CVE-2021-22978?

CVE-2021-22978 has a CVSS 3.x base score of 8.3, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-22978 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22978?

CVE-2021-22978 primarily affects F5 Big-ip Access Policy Manager. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-22978?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-22978 published?

CVE-2021-22978 was published on 2021-02-12 and last updated on 2026-06-17.

CVE-2021-22978

CVE-2021-22978 is a high-severity vulnerability in F5 Big-ip Access Policy Manager with a CVSS 3.x base score of 8.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: High (CVSS 3.x base score 8.3)
CVSS v2: 5.1
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: F5 Big-ip Access Policy Manager
Published: 2021-02-12
Last modified: 2026-06-17

Description

On BIG-IP version 16.0.x before 16.0.1, 15.1.x before 15.1.1, 14.1.x before 14.1.3.1, 13.1.x before 13.1.3.5, and all 12.1.x and 11.6.x versions, undisclosed endpoints in iControl REST allow for a reflected XSS attack, which could lead to a complete compromise of BIG-IP if the victim user is granted the admin role. Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.

Frequently asked questions

What is CVE-2021-22978?: On BIG-IP version 16.0.x before 16.0.1, 15.1.x before 15.1.1, 14.1.x before 14.1.3.1, 13.1.x before 13.1.3.5, and all 12.1.x and 11.6.x versions, undisclosed endpoints in iControl REST allow for a reflected XSS attack, which could lead to a complete compromise of BIG-IP if the victim user is granted the admin role. Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.
How severe is CVE-2021-22978?: CVE-2021-22978 has a CVSS 3.x base score of 8.3, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-22978 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22978?: CVE-2021-22978 primarily affects F5 Big-ip Access Policy Manager. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-22978?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-22978 published?: CVE-2021-22978 was published on 2021-02-12 and last updated on 2026-06-17.

References

https://support.f5.com/csp/article/K87502622

Affected products (14)

cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_web_application_firewall:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_ddos_hybrid_defender:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_fraud_protection_service:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_global_traffic_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_link_controller:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_local_traffic_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_policy_enforcement_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_ssl_orchestrator:*:*:*:*:*:*:*:*

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