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% (80th 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% (80th 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% (80th 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:*:*:*:*:*:*:*:*

More vulnerabilities in F5 Big-ip Advanced Web Application Firewall

CVE-2023-41373 — Critical (CVSS 9.9): A directory traversal vulnerability exists in the BIG-IP Configuration Utility that may allow an authenticated attacker…
CVE-2021-22987 — Critical (CVSS 9.9): On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, 12.1.x…
CVE-2023-46747 — Critical (CVSS 9.8): Undisclosed requests may bypass configuration utility authentication, allowing an attacker with network access to the…
CVE-2021-22991 — Critical (CVSS 9.8): On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, and…
CVE-2021-22992 — Critical (CVSS 9.8): On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, 12.1.x…
CVE-2021-22986 — Critical (CVSS 9.8): On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, and…

All CVEs affecting F5 Big-ip Advanced Web Application Firewall →

Other CWE-78 (OS Command Injection) vulnerabilities

CVE-2026-19188 — Critical (CVSS 10.0): A critical OS command injection vulnerability has been identified in the Haiwell IoT Cloud HMI Gateway product. The…
CVE-2026-48362 — Critical (CVSS 10.0): ColdFusion is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')…
CVE-2026-16812 — Critical (CVSS 10.0): VeloCloud Orchestrator (VCO) on-prem has a security issue where this issue may allow a remote attacker to access…
CVE-2026-6516 — Critical (CVSS 10.0): Zohocorp ManageEngine ADAudit Plus versions before 8606 are affected by Unauthenticated Remote code execution due to…
CVE-2026-46339 — Critical (CVSS 10.0): 9Router is an AI router & token saver. From 0.4.30 until 0.4.37, 9Router's src/proxy.js middleware did not protect…
CVE-2026-59726 — Critical (CVSS 10.0): Ruflo is an agent meta-harness for Claude Code and Codex. Prior to 3.16.3, ruflo's default docker-compose deployment…

Browse all CWE-78 (OS Command Injection) vulnerabilities →