How severe is CVE-2021-23030?

CVE-2021-23030 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-23030 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-23030?

CVE-2021-23030 primarily affects F5 Big-ip Advanced Web Application Firewall. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-23030?

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-2021-23030 published?

CVE-2021-23030 was published on 2021-09-14 and last updated on 2026-06-17.

CVE-2021-23030

CVE-2021-23030 is a high-severity vulnerability in F5 Big-ip Advanced Web Application Firewall with a CVSS 3.x base score of 7.5. 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-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: F5 Big-ip Advanced Web Application Firewall
Published: 2021-09-14
Last modified: 2026-06-17

Description

On BIG-IP Advanced WAF and BIG-IP ASM version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.3, 13.1.x before 13.1.4.1, and all versions of 12.1.x, when a WebSocket profile is configured on a virtual server, undisclosed requests can cause bd to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Frequently asked questions

What is CVE-2021-23030?: On BIG-IP Advanced WAF and BIG-IP ASM version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.3, 13.1.x before 13.1.4.1, and all versions of 12.1.x, when a WebSocket profile is configured on a virtual server, undisclosed requests can cause bd to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
How severe is CVE-2021-23030?: CVE-2021-23030 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-23030 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-23030?: CVE-2021-23030 primarily affects F5 Big-ip Advanced Web Application Firewall. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-23030?: 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-2021-23030 published?: CVE-2021-23030 was published on 2021-09-14 and last updated on 2026-06-17.

References

https://support.f5.com/csp/article/K42051445

Affected products (2)

cpe:2.3:a:f5:big-ip_advanced_web_application_firewall:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*

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