CVE-2020-3580 — Adaptive Security Appliance Software
MEDIUMCVE-2020-3580 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in cisco adaptive security appliance software. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) and has been used in ransomware campaigns — treat it as actively exploited and patch now. A fix is available — see the affected versions and patch details below.
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,…
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03 — including use in ransomware campaigns. Federal agencies were required to remediate by 2022-05-03.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2020-3580.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-3580 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Counts from FIRST.org, log-scaled.
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.
Affected Products
adaptive security appliance softwareciscosecure firewall threat defenseciscoResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every cisco adaptive security appliance software deployment and check each version against the affected-products list above.
Fix
Apply the cisco adaptive security appliance software security patch or hotfix for CVE-2020-3580 on the affected version, following the vendor advisory for your exact build.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
How to detect CVE-2020-3580
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2020-3580 -u https://target- Template
- Cisco ASA/FTD Software - Cross-Site Scripting
- Severity
- medium
- Impact
- Successful exploitation of this vulnerability could allow an attacker to execute arbitrary script code in the context of a targeted user's browser, potentially leading to session hijacking, defacement, or theft of sensitive information.
- Remediation
- Apply the latest security patches or updates provided by Cisco to mitigate this vulnerability.
Template by ProjectDiscovery nuclei-templates (pikpikcu), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2020-3580 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.