{"id":"CVE-2023-20269","kind":"vulnerability","aliases":["CVE-2023-20269"],"related":[],"title":"cisco adaptive security appliance software: A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco…","description":"A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct a brute force attack in an attempt to identify valid username and password combinations or an authenticated, remote attacker to establish a clientless SSL VPN session with an unauthorized user.\r\n\r This vulnerability is due to improper separation of authentication, authorization, and accounting (AAA) between the remote access VPN feature and the HTTPS management and site-to-site VPN features. An attacker could exploit this vulnerability by specifying a default connection profile/tunnel group while conducting a brute force attack or while establishing a clientless SSL VPN session using valid credentials. A successful exploit could allow the attacker to achieve one or both of the following:\r\n\r \r Identify valid credentials that could then be used to establish an unauthorized remote access VPN session.\r Establish a clientless SSL VPN session (only when running Cisco ASA Software Release 9.16 or earlier).\r \r Notes:\r\n\r \r Establishing a client-based remote access VPN tunnel is not possible as these default connection profiles/tunnel groups do not and cannot have an IP address pool configured.\r This vulnerability does not allow an attacker to bypass authentication. To successfully establish a remote access VPN session, valid credentials are required, including a valid second factor if multi-factor authentication (MFA) is configured.\r \r Cisco will release software updates that address this vulnerability. There are workarounds that address this vulnerability.","summary":"Cisco ASA and Firepower Threat Defense firewalls contain an unauthorized access flaw that lets an unauthenticated remote attacker brute-force valid username and password pairs or open a clientless SSL VPN session as an unauthorized user. CISA lists it as known exploited, with ransomware use noted in its catalog tags.","severity":"critical","cvss":9.1,"epss":null,"exploited":true,"exploited_at":"2023-09-13T00:00:00+00:00","products":[{"name":"Cisco Adaptive Security Appliance and Firepower Threat Defense","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.1","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.1.5","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.1.7","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.8","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.14","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.15","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.17","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.20","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.24","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.26","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.28","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.33","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.35","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.2.38","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.3","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.3.8","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.3.11","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.3.14","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.3.16","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.3.18","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.3.21","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.3.26","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.3.29","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.3","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.7","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.8","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.10","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.12","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.15","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.17","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.20","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.22","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.25","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.26","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.29","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.32","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.33","ecosystem":"vendor"},{"name":"cisco adaptive security appliance software","fixed":[],"affected":"= 9.8.4.34","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["asa","cisco","clientless-ssl-vpn","exploited","firepower","infrastructure","ransomware","self-hosted"],"not_affected_if":["managed-hosting","no-clientless-ssl-vpn"],"how_to_check":null,"fix":"Apply the vendor mitigations for group-lock and vpn-simultaneous-logins per Cisco's advisory, or retire unsupported devices. Exact fixed versions: unknown from sources.","status":"open","published_at":"2023-09-06T18:15:08+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T21:04:41+00:00","updated_at":"2026-10-23T22:29:04+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:04:41Z","model":"claude-haiku-5-5","output":{"fix":"Apply the vendor mitigations for group-lock and vpn-simultaneous-logins per Cisco's advisory, or retire unsupported devices. Exact fixed versions: unknown from sources.","reach":"internet","impact":"high","summary":"Cisco ASA and Firepower Threat Defense firewalls contain an unauthorized access flaw that lets an unauthenticated remote attacker brute-force valid username and password pairs or open a clientless SSL VPN session as an unauthorized user. CISA lists it as known exploited, with ransomware use noted in its catalog tags.","category":"infrastructure","who_cares":["cisco","asa","firepower","clientless-ssl-vpn","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker gains unauthorized VPN session access to the network behind the firewall","analyst_note":"Pull the Cisco security advisory for CVE-2023-20269 to confirm affected versions, fixed releases and exact group-lock and vpn-simultaneous-logins commands; the KEV entry alone gives no version or check steps.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["no-clientless-ssl-vpn","managed-hosting"],"user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000528,"input_tokens":2939,"output_tokens":469,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2023':24A,27A '-20269':25A,28A '9.16':465C 'aaa':373C 'access':11A,260B,306C,377C,449C,475C,512C 'account':372C 'achiev':429C 'adapt':2A,16A,311C 'adaptive':30A,38A,43A,48A,53A,58A,63A,68A,73A,78A,83A,88A,93A,98A,103A,108A,113A,118A,123A,128A,133A,138A,143A,148A,153A,158A,163A,168A,173A,178A,183A,188A,193A,198A,203A,208A,213A,218A,223A,228A,233A 'address':494C,538C,545C 'allow':324C,425C,501C 'and':33A 'applianc':4A,18A,313C 'appliance':32A,40A,45A,50A,55A,60A,65A,70A,75A,80A,85A,90A,95A,100A,105A,110A,115A,120A,125A,130A,135A,140A,145A,150A,155A,160A,165A,170A,175A,180A,185A,190A,195A,200A,205A,210A,215A,220A,225A,230A,235A 'asa':19A,237B,251B,314C,462C 'attack':267B,328C,334C,349C,392C,409C,427C,503C 'attempt':337C 'authent':347C,369C,506C,528C 'author':370C 'base':473C 'brute':269B,332C,407C 'brute-forc':268B 'bypass':505C 'cannot':490C 'catalog':299B 'cisa':287B 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'multi':526C 'multi-factor':525C 'note':296B,468C 'one':430C 'open':277B 'pair':275B 'password':274B,343C 'pool':495C 'possibl':480C 'profile/tunnel':402C 'profiles/tunnel':485C 'ransomwar':246B,294B 'releas':464C,534C 'remot':10A,266B,305C,327C,348C,376C,448C,474C,511C 'requir':518C 'run':460C 'second':522C 'secur':3A,17A,312C 'security':31A,39A,44A,49A,54A,59A,64A,69A,74A,79A,84A,89A,94A,99A,104A,109A,114A,119A,124A,129A,134A,139A,144A,149A,154A,159A,164A,169A,174A,179A,184A,189A,194A,199A,204A,209A,214A,219A,224A,229A,234A 'self':248B 'self-host':247B 'separ':367C 'session':282B,356C,417C,451C,457C,514C 'site':386C,388C 'site-to-sit':385C 'softwar':5A,20A,315C,322C,463C,535C 'software':41A,46A,51A,56A,61A,66A,71A,76A,81A,86A,91A,96A,101A,106A,111A,116A,121A,126A,131A,136A,141A,146A,151A,156A,161A,166A,171A,176A,181A,186A,191A,196A,201A,206A,211A,216A,221A,226A,231A,236A 'specifi':398C 'ssl':241B,280B,354C,415C,455C 'success':422C,508C 'tag':300B 'threat':35A,254B,319C 'tunnel':477C 'unauthent':265B,326C 'unauthor':259B,285B,359C,447C 'updat':536C 'use':295B,418C,443C 'user':286B,360C 'usernam':272B,341C 'valid':271B,340C,419C,437C,515C,521C 'vpn':12A,242B,281B,307C,355C,378C,389C,416C,450C,456C,476C,513C 'vulner':7A,302C,362C,396C,498C,540C,547C 'workaround':543C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2023-09-06T18:15:08+00:00","kev":{"dateAdded":"2023-09-13","dueDate":"2023-10-04","requiredAction":"Apply mitigations per vendor instructions for group-lock and vpn-simultaneous-logins or discontinue use of the product for unsupported devices.","knownRansomwareCampaignUse":"Known"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","cvss_by":"psirt@cisco.com","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2023-20269","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-20269","severity":null,"published_at":"2023-09-13T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T13:39:30+00:00","note":null},{"source":"nvd","external_id":"CVE-2023-20269","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-20269","severity":null,"published_at":"2023-09-06T18:15:08+00:00","modified_at":"2026-08-11T19:33:44+00:00","first_seen_at":"2026-10-23T22:29:04+00:00","fetched_at":"2026-10-23T22:29:04+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"}