--- id: "CVE-2025-20333" kind: "vulnerability" aliases: ["CVE-2025-20333"] title: "A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco\u2026" severity: "critical" cvss: 9.9 epss: null exploited: true status: "open" category: "infrastructure" products: [{"name": "Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": ["9.12.4.72"], "affected": ">= 9.12, < 9.12.4.72", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": ["9.14.4.28"], "affected": ">= 9.14, < 9.14.4.28", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": ["9.16.4.85"], "affected": ">= 9.16, < 9.16.4.85", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": ["9.17.1.45"], "affected": ">= 9.17.0, < 9.17.1.45", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": ["9.18.4.47"], "affected": ">= 9.18, < 9.18.4.47", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": ["9.19.1.37"], "affected": ">= 9.19, < 9.19.1.37", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": ["9.20.3.7"], "affected": ">= 9.20, < 9.20.3.7", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": ["9.22.1.3"], "affected": ">= 9.22, < 9.22.1.3", "ecosystem": "vendor"}, {"name": "cisco secure firewall threat defense", "fixed": ["7.0.8.1"], "affected": ">= 7.0.0, < 7.0.8.1", "ecosystem": "vendor"}, {"name": "cisco secure firewall threat defense", "fixed": ["7.2.9"], "affected": ">= 7.1.0, < 7.2.9", "ecosystem": "vendor"}, {"name": "cisco secure firewall threat defense", "fixed": ["7.4.2.4"], "affected": ">= 7.3.0, < 7.4.2.4", "ecosystem": "vendor"}, {"name": "cisco secure firewall threat defense", "fixed": [], "affected": "= 7.6.0", "ecosystem": "vendor"}] ecosystems: ["vendor"] tags: ["asa", "cisco", "exploited", "firewall", "ftd", "infrastructure", "vpn"] not_affected_if: ["no-vpn-web-server"] published_at: "2025-09-25T00:00:00+00:00" first_seen_at: "2026-10-23T19:11:51+00:00" updated_at: "2026-10-23T23:44:51+00:00" sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-20333", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-20333", "first_seen_at": "2026-10-23T23:44:51+00:00"}] --- # A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco… Cisco ASA and Secure Firewall Threat Defense VPN web server has a buffer overflow that allows remote code execution. The sources say it is being exploited in the wild and can be chained with CVE-2025-20362. _Summary, check and fix written by a model from the sources; labelled as such._ ## Affected - vendor:Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense affected ? fixed ? - vendor:cisco adaptive security appliance software affected >= 9.12, < 9.12.4.72 fixed 9.12.4.72 - vendor:cisco adaptive security appliance software affected >= 9.14, < 9.14.4.28 fixed 9.14.4.28 - vendor:cisco adaptive security appliance software affected >= 9.16, < 9.16.4.85 fixed 9.16.4.85 - vendor:cisco adaptive security appliance software affected >= 9.17.0, < 9.17.1.45 fixed 9.17.1.45 - vendor:cisco adaptive security appliance software affected >= 9.18, < 9.18.4.47 fixed 9.18.4.47 - vendor:cisco adaptive security appliance software affected >= 9.19, < 9.19.1.37 fixed 9.19.1.37 - vendor:cisco adaptive security appliance software affected >= 9.20, < 9.20.3.7 fixed 9.20.3.7 - vendor:cisco adaptive security appliance software affected >= 9.22, < 9.22.1.3 fixed 9.22.1.3 - vendor:cisco secure firewall threat defense affected >= 7.0.0, < 7.0.8.1 fixed 7.0.8.1 - vendor:cisco secure firewall threat defense affected >= 7.1.0, < 7.2.9 fixed 7.2.9 - vendor:cisco secure firewall threat defense affected >= 7.3.0, < 7.4.2.4 fixed 7.4.2.4 - vendor:cisco secure firewall threat defense affected = 7.6.0 fixed ? ## Timeline - 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-20333 - 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2025-20333 ## From the sources Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Software VPN Web Server contain a buffer overflow vulnerability that allows for remote code execution. This vulnerability could be chained with CVE-2025-20362. CISA required action: The KEV due date refers to the deadline by which FCEB agencies are expected to review and begin implementing the guidance outlined in Emergency Directive (ED) 25-03 (URL listed below in Notes). Agencies must follow the mitigation steps provided by CISA (URL listed below in Notes) and vendor’s instructions (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available. --- _Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_