{"id":"CVE-2020-3580","published":"2020-10-21T19:15:18Z","modified":"2026-08-11T19:42:47Z","title":"Cisco ASA and FTD Cross-Site Scripting (XSS) Vulnerability","vendor":"Cisco","product":"Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)","tier":"core","eol":null,"description":{"text":"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.","provenance":"source","from":"NVD"},"summary":{"text":"The flaw is cross-site scripting in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software, caused by insufficient validation of user-supplied input, and it affects only specific AnyConnect and WebVPN configurations. An unauthenticated remote attacker can exploit it by persuading a user of the interface to click a crafted link, which could let them run arbitrary script in the context of the interface or access sensitive browser-based information.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-29T08:31:35Z"},"cvss":{"score":6.1,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","provenance":"source","from":"NVD"},"epss":{"score":0.85575,"percentile":0.99723,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2021-11-03","dueDate":"2022-05-03","ransomware":true,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2020-3580","provenance":"source"},"vulncheckKev":{"dateAdded":"2021-11-03","exploitedFirstSeen":"2021-11-03","ransomware":true,"evidence":[{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2021-11-03"},{"url":"https://dashboard.shadowserver.org/statistics/honeypot/vulnerability/map/?day=2023-11-15&host_type=src&vulnerability=cve-2020-3580","date":"2023-11-15"},{"url":"https://dashboard.shadowserver.org/statistics/honeypot/vulnerability/map/?day=2024-01-22&host_type=src&vulnerability=cve-2020-3580","date":"2024-01-22"},{"url":"https://dashboard.shadowserver.org/statistics/honeypot/vulnerability/map/?day=2024-01-23&host_type=src&vulnerability=cve-2020-3580","date":"2024-01-23"},{"url":"https://dashboard.shadowserver.org/statistics/honeypot/vulnerability/map/?day=2024-01-24&host_type=src&vulnerability=cve-2020-3580","date":"2024-01-24"},{"url":"https://dashboard.shadowserver.org/statistics/honeypot/vulnerability/map/?day=2024-01-27&host_type=src&vulnerability=cve-2020-3580","date":"2024-01-27"},{"url":"https://dashboard.shadowserver.org/statistics/honeypot/vulnerability/map/?day=2024-01-28&host_type=src&vulnerability=cve-2020-3580","date":"2024-01-28"},{"url":"https://dashboard.shadowserver.org/statistics/honeypot/vulnerability/map/?day=2024-01-29&host_type=src&vulnerability=cve-2020-3580","date":"2024-01-29"},{"url":"https://dashboard.shadowserver.org/statistics/honeypot/vulnerability/map/?day=2024-01-30&host_type=src&vulnerability=cve-2020-3580","date":"2024-01-30"},{"url":"https://dashboard.shadowserver.org/statistics/honeypot/vulnerability/map/?day=2024-01-31&host_type=src&vulnerability=cve-2020-3580","date":"2024-01-31"}],"evidenceTotal":438,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-xss-multiple-FCB3vPZe","tags":["Patch","Vendor Advisory"]},{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-xss-multiple-FCB3vPZe","tags":["Patch","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3580","tags":["US Government Resource"]}],"techniques":[{"id":"T1204.001","name":"Malicious Link","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Cross-site Scripting (XSS)","mappingType":"exploitation_technique","evidence":[],"comment":"CVE-2020-3580 is a vulnerability affecting the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link to to execute arbitrary script code within the interface\nor access sensitive browser-based information. ","confidence":"high"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Cross-site Scripting (XSS)","mappingType":"primary_impact","evidence":[],"comment":"CVE-2020-3580 is a vulnerability affecting the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link to to execute arbitrary script code within the interface\nor access sensitive browser-based information. ","confidence":"high"},{"id":"T1217","name":"Browser Information Discovery","tactics":["discovery"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Cross-site Scripting (XSS)","mappingType":"secondary_impact","evidence":[],"comment":"CVE-2020-3580 is a vulnerability affecting the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link to to execute arbitrary script code within the interface\nor access sensitive browser-based information. ","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2020-24851","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-24851","exploited":true,"exploitedSince":"2021-11-03","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":4,"skipped":0,"earliest":"2021-06-25","earliestUrl":"https://github.com/Hudi233/CVE-2020-3580","repos":[{"name":"adarshvs/CVE-2020-3580","url":"https://github.com/adarshvs/CVE-2020-3580","stars":19,"created":"2021-06-28"},{"name":"Hudi233/CVE-2020-3580","url":"https://github.com/Hudi233/CVE-2020-3580","stars":9,"created":"2021-06-25"},{"name":"catatonicprime/CVE-2020-3580","url":"https://github.com/catatonicprime/CVE-2020-3580","stars":2,"created":"2022-07-15"},{"name":"cruxN3T/CVE-2020-3580","url":"https://github.com/cruxN3T/CVE-2020-3580","stars":0,"created":"2022-06-24"}]},"nuclei":[{"id":"CVE-2020-3580","name":"Cisco ASA/FTD Software - Cross-Site Scripting","severity":"medium","path":"http/cves/2020/CVE-2020-3580.yaml","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2020/CVE-2020-3580.yaml"}],"first":{"date":"2021-06-25","source":"PoC-in-GitHub","url":"https://github.com/Hudi233/CVE-2020-3580"},"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1204.001"],"provenance":"source"},{"stage":"primary","techniques":["T1059"],"provenance":"source"},{"stage":"secondary","techniques":["T1217"],"provenance":"source"}],"timeline":[{"date":"2020-10-21","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-3580","provenance":"source"},{"date":"2021-06-25","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub","url":"https://github.com/Hudi233/CVE-2020-3580","provenance":"source"},{"date":"2021-11-03","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","provenance":"source"},{"date":"2021-11-03","kind":"kev","label":"Added to CISA KEV (known ransomware use)","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2021-11-03","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-24851","provenance":"source"}],"speed":{"daysToPublicExploit":247,"firstExploitFrom":"PoC-in-GitHub","daysToKev":378},"priority":{"score":77.2,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 1821 days ago"},{"name":"Known ransomware use","points":10.0,"detail":"CISA KEV and VulnCheck KEV: Known"},{"name":"EPSS percentile","points":19.94,"detail":"percentile 0.9972"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"4 PoC-in-GitHub repos; 1 nuclei template"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":4.27,"detail":"base score 6.1"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]},"lineage":{"familyId":"fam-class-cisco-asa-cwe-79"}}