CVE-2020-3580
Cisco ASA and FTD Cross-Site Scripting (XSS) Vulnerability
What the flaw is
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an insufficient input validation vulnerability for user-supplied input by the web services interface. Successful exploitation could allow an attacker to perform cross-site scripting (XSS) in the context of the interface or access sensitive browser-based information.
Description as published by CISA. We have not independently reproduced it.
What CISA requires
Apply updates per vendor instructions.
This deadline is binding on US federal civilian agencies under BOD 22-01. It is not a legal deadline for anyone else, but it is a useful urgency signal — CISA sets it by how actively the flaw is being used, not by CVSS.
Public exploit code
21 public repositories referencing this CVE have been catalogued on GitHub. Treat this as a strong signal to prioritise patching, not as a verified working exploit — many such repositories are scanners, write-ups or forks rather than functional code.
- 20142995/nuclei-templates
- ARPSyndicate/cve-scores
- ARPSyndicate/cvemon
- ARPSyndicate/kenzer-templates
- CLincat/vulcat
- Hudi233/CVE-2020-3580
- Ostorlab/KEV
- Ostorlab/known_exploited_vulnerbilities_detectors
Showing 8 of 21. Full list in the trickest/cve dataset.
Vendor advisories
Primary sources
Was this page helpful?
If something here is wrong or out of date, tell us and we will check the source.
Thanks — that is recorded.
Other Cisco entries
See allSecure Firewall Management Center (FMC)
Use of Hard-coded Password
CVE-2008-4128IOS
Cross-Site Request Forgery
CVE-2026-20230Unified Communications Manager
Server-Side Request Forgery (SSRF)
CVE-2026-20262Catalyst SD-WAN Manager
Directory or Path Traversal
CVE-2026-20245Catalyst SD-WAN Manager
Improper Encoding or Escaping of Output
CVE-2026-20182Catalyst SD-WAN
Controller Authentication Bypass
Source: CISA KEV catalog · last verified August 6, 2026. Rebuilt automatically twice a day.