CVE intelligence and bounded remediation

CVE-2021-22993 — F5 Big-Ip Advanced Web Application Firewall security vulnerability

High CVSS 8.8

On BIG-IP Advanced WAF and BIG-IP ASM versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2, 14.1.x before 14.1.3.1, 13.1.x before 13.1.3.6, and 12.1.x before 12.1.5.3, DOM-based XSS on DoS Profile properties page. Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.

Severity
High
CVSS
8.8 (3.1)
Published
2021-03-31
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-79

Affected products

  • f5 / big-ip_advanced_web_application_firewall
  • f5 / big-ip_application_security_manager

Showing 2 representative product identities from 10 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Cross-site scripting and unsafe browser output

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Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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