How severe is CVE-2021-23031?

CVE-2021-23031 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-23031 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-23031?

CVE-2021-23031 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-2021-23031?

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

When was CVE-2021-23031 published?

CVE-2021-23031 was published on 2021-09-14 and last updated on 2026-06-17.

CVE-2021-23031

CVE-2021-23031 is a critical-severity vulnerability in F5 Big-ip Advanced Web Application Firewall with a CVSS 3.x base score of 9.9. 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-78.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
CVSS v2: 6.5
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: F5 Big-ip Advanced Web Application Firewall
Published: 2021-09-14
Last modified: 2026-06-17

Description

On version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3, 14.1.x before 14.1.4.1, 13.1.x before 13.1.4, 12.1.x before 12.1.6, and 11.6.x before 11.6.5.3, an authenticated user may perform a privilege escalation on the BIG-IP Advanced WAF and ASM Configuration utility. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Frequently asked questions

What is CVE-2021-23031?: On version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3, 14.1.x before 14.1.4.1, 13.1.x before 13.1.4, 12.1.x before 12.1.6, and 11.6.x before 11.6.5.3, an authenticated user may perform a privilege escalation on the BIG-IP Advanced WAF and ASM Configuration utility. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
How severe is CVE-2021-23031?: CVE-2021-23031 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-23031 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-23031?: CVE-2021-23031 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-2021-23031?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-23031 published?: CVE-2021-23031 was published on 2021-09-14 and last updated on 2026-06-17.

References

https://support.f5.com/csp/article/K41351250

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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