CVE-2021-23028

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-09-14 · updated 2026-06-17
Weakness: CWE-20

Description

On version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.2, and 13.1.x before 13.1.4, when JSON content profiles are configured for URLs as part of an F5 Advanced Web Application Firewall (WAF)/BIG-IP ASM security policy and applied to a virtual server, undisclosed requests may cause the BIG-IP ASM bd process to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Affected products

F5 Big-Ip Advanced Web Application Firewall: from 13.1.3.5 through 13.1.3.6; from 14.1.3.1 through 14.1.4.1; from 15.1.1 before 15.1.3.1; 16.0.1 — fixed in 15.1.3.1
BIG-IP ASM: from 13.1..3.5 through 13.1.3.6; from 14.1.3.1 through 14.1.4.1; from 15.1.0 before 15.1.3.1; 16.0.1 — fixed in 15.1.3.1

How to fix

Upgrade to a fixed version: F5 Big-Ip Advanced Web Application Firewall 15.1.3.1; BIG-IP ASM 15.1.3.1. Check the vendor advisory for mitigations.

References

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