CVE-2020-3580: in the CISA KEV catalogue
Cisco ASA and FTD Cross-Site Scripting (XSS) Vulnerability. CISA added CVE-2020-3580 to the Known Exploited Vulnerabilities catalogue on 2021-11-03 with a default due date of 2022-05-03. Known ransomware campaign use: Known. Forensic triage flag: No.
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. (CISA description)
- Vendor / product
- Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)
- CWE
- CWE-79
- CISA required action
- Apply updates per vendor instructions.
- EPSS
- 86%, percentile 99 (scored 2026-11-04)
EPSS puts about 86 in 100 odds (86%) on exploitation activity being observed in the next 30 days. Its score is higher than or equal to that of 99% of scored CVEs. This is a model estimate about exploitation anywhere, not about your environment.
Vendor and reference links (from CISA)
Your own deadline under CISA BOD 26-04 depends on exposure, automatability and technical impact: work it out with the BOD 26-04 calculator.
Frequently asked questions
Is CVE-2020-3580 in the CISA KEV catalogue?
Yes. CISA added CVE-2020-3580 (Cisco ASA and FTD Cross-Site Scripting (XSS) Vulnerability) to the Known Exploited Vulnerabilities catalogue on 2021-11-03. CISA's default due date for it is 2022-05-03.
Is CVE-2020-3580 used in ransomware attacks?
CISA marks known ransomware campaign use as Known for CVE-2020-3580.
What should I do about CVE-2020-3580?
CISA's required action: Apply updates per vendor instructions.
Sources
- CISA, Known Exploited Vulnerabilities Catalog (accessed 2026-11-03)
- FIRST, Exploit Prediction Scoring System (EPSS) (EPSS by FIRST; scores generated by Empirical Security)
- NVD record for CVE-2020-3580