CVE-2020-3580
Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Interface Cross-Site Scripting Vulnerabilities
- Medium 6.1
- Exploited: added to CISA KEV 3 Nov 2021
- Used in ransomware campaigns
Description
Multiple vulnerabilities in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct cross-site scripting (XSS) attacks against a user of the web services interface of an affected device. The vulnerabilities are due to insufficient validation of user-supplied input by the web services interface of an affected device. An attacker could exploit these vulnerabilities by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or allow the attacker to access sensitive, browser-based information. Note: These vulnerabilities affect only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section.
Key facts
- Published
- 21 Oct 2020
- Last changed
- 21 Oct 2025
- Assigned by
- cisco
- KEV added
- 3 Nov 2021
- KEV fix due
- 3 May 2022
- Used in ransomware
- Yes, according to CISA
- EPSS
- 85.575% likely to be exploited in the next 30 days, higher than 99.729% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: no; Technical impact: partial
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 6.1CVSS 3.1, Mediumfrom the CNA (cisco)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
What to do
- Apply updates per vendor instructions.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) Software |
|
Timeline
- 21 Oct 2020 Published
- 3 Nov 2021 CVE-2020-3580 added to CISA KEV
- 3 Nov 2021 Added to the CISA KEV catalogue
Weakness
Practice this bug class
HackZoneLabs has a hands-on lab on XSS (stored, reflected, DOM) (CWE-79).