{"id":"CVE-2020-3580","kind":"vulnerability","aliases":["CVE-2020-3580"],"related":[],"title":"Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD): Cisco ASA and FTD Cross-Site Scripting (XSS) Vulnerability","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.","summary":"Cisco ASA and Firepower Threat Defense web services interface does not validate user input, allowing cross-site scripting. An attacker can run script in an administrator's browser session on the interface or read sensitive browser-based information.","severity":"high","cvss":6.1,"epss":0.85575,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["asa","cisco","exploited","firepower-threat-defense","infrastructure","network-appliance","ransomware"],"not_affected_if":["web-services-disabled"],"how_to_check":null,"fix":"Apply the Cisco updates per vendor instructions; the specific fixed versions are not stated in the sources.","status":"open","published_at":"2020-10-21T19:15:18+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:43:26+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:43:26Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Cisco updates per vendor instructions; the specific fixed versions are not stated in the sources.","reach":"network","impact":"medium","summary":"Cisco ASA and Firepower Threat Defense web services interface does not validate user input, allowing cross-site scripting. An attacker can run script in an administrator's browser session on the interface or read sensitive browser-based information.","category":"infrastructure","who_cares":["cisco","asa","firepower-threat-defense","network-appliance"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Attacker runs script in admin browser session and reads sensitive data","analyst_note":"Find the Cisco advisory for CVE-2020-3580 for affected and fixed versions and the check for whether the web services interface is enabled.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["web-services-disabled"],"user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000471,"input_tokens":2962,"output_tokens":350,"severity_before":"unknown"},"analyst_status":"queued","analyst_note":"Find the Cisco advisory for CVE-2020-3580 for affected and fixed versions and the check for whether the web services interface is enabled.","search":"'-2020':22A,25A '-3580':23A,26A 'access':198C 'adapt':2A,98C 'adaptive':28A 'administr':75B 'affect':134C,155C,207C 'allow':63B,111C,179C,194C 'and':32A 'anyconnect':210C 'applianc':4A,47B,100C 'appliance':30A 'arbitrari':184C 'asa':5A,12A,31A,37B,50B,101C 'attack':69B,115C,123C,158C,181C,196C 'base':87B,202C 'browser':77B,86B,201C 'browser-bas':85B,200C 'cisco':1A,11A,27A,38B,49B,97C,104C 'click':171C 'code':186C 'conduct':117C 'configur':213C 'context':189C 'could':110C,159C,178C 'craft':173C 'cross':16A,65B,119C 'cross-sit':15A,64B,118C 'cve':21A,24A 'defens':9A,43B,54B,107C 'defense':35A 'devic':135C,156C 'due':139C 'execut':183C 'exploit':39B,160C,177C 'firepow':7A,41B,52B,105C 'firepower':33A 'firepower-threat-defens':40B 'ftd':10A,14A,36A,108C 'inform':88B,203C,216C 'infrastructur':44B 'input':62B,147C 'insuffici':141C 'interfac':57B,81B,95C,131C,152C,169C,192C 'link':174C 'multipl':89C 'network':46B 'network-appli':45B 'note':204C 'persuad':164C 'product':220C 'ransomwar':48B 'read':83B 'remot':114C 'run':71B 'script':18A,67B,72B,121C,185C 'section':221C 'secur':3A,99C 'security':29A 'see':217C 'sensit':84B,199C 'servic':56B,94C,130C,151C 'session':78B 'site':17A,66B,120C 'softwar':102C,109C 'specif':209C 'success':176C 'suppli':146C 'threat':8A,34A,42B,53B,106C 'unauthent':113C 'user':61B,126C,145C,166C 'user-suppli':144C 'valid':60B,142C 'vulner':20A,90C,137C,162C,206C,219C 'web':55B,93C,129C,150C 'webvpn':212C 'xss':19A,122C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2020-10-21T19:15:18+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2022-05-03","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Known"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","cvss_by":"psirt@cisco.com","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2020-3580","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-3580","severity":null,"published_at":"2021-11-03T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:53+00:00","fetched_at":"2026-10-25T15:39:43+00:00","note":null},{"source":"epss","external_id":"CVE-2020-3580","url":"https://api.first.org/data/v1/epss?cve=CVE-2020-3580","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2020-3580","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-3580","severity":null,"published_at":"2020-10-21T19:15:18+00:00","modified_at":"2026-08-11T19:42:47+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}