What is the CVSS score of CVE-2025-20362?

CVE-2025-20362 has a CVSS 3.1 base score of 8.6 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H. EPSS exploitation probability: 43.6%.

Which versions of Cisco ASA/FTD are affected by CVE-2025-20362?

Cisco ASA and Firepower Threat Defense VPN appliances contain an unauthenticated vulnerability confirmed actively exploited (CISA KEV) that allows attackers to access internal VPN endpoints without…

Is there a public PoC exploit available for CVE-2025-20362?

Yes, a public proof-of-concept exploit is available for CVE-2025-20362. Prioritise patching immediately. EPSS: 43.6%.

How to fix or mitigate CVE-2025-20362?

Within 24 hours: Audit all Cisco ASA and FTD appliances in production, restrict VPN management web interfaces to trusted administrative networks via firewall rules, and configure SIEM alerts for unauthorized access attempts to VPN endpoints. Within 7 days: Implement strict network segmentation isolating VPN web server endpoints from untrusted networks; deploy IPS/IDS signatures for CVE-2025-20362 (check Cisco security advisories); disable non-essential VPN web services if operationally feasible. Within 30 days: Maintain monitoring for vendor patch availability and establish a patching timeline upon release; if Cisco patch delay exceeds 30 days, evaluate contingency options including temporary migration of critical VPN services to alternative secure platforms.

Cisco ASA/FTD CVE-2025-20362

HIGH

Missing Authorization (CWE-862)

2025-09-25 psirt@cisco.com

Authentication Bypass Denial Of Service Cisco Adaptive Security Appliance Software Firepower Threat Defense

8.6

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.6 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

vuln.today AI

8.6 HIGH

Network-reachable VPN listener, no credentials required, no interaction needed; High availability from device-reload DoS variant; Low C/I from restricted URL access without full compromise.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

Primary rating from NVD.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

High

Lifecycle Timeline

Analysis Updated

Aug 11, 2026 - 19:44 vuln.today

v2 (cvss_changed)

Re-analysis Queued

Aug 11, 2026 - 19:37 vuln.today

cvss_changed

Severity Changed

Aug 11, 2026 - 19:37 NVD

MEDIUM HIGH

CVSS changed

Aug 11, 2026 - 19:37 NVD

6.5 (MEDIUM) 8.6 (HIGH)

Analysis Generated

Mar 28, 2026 - 19:14 vuln.today

Added to CISA KEV

Nov 06, 2025 - 14:51 cisa

CISA KEV

PoC Detected

Nov 06, 2025 - 14:51 vuln.today

Public exploit code

CVE Published

Sep 25, 2025 - 16:15 nvd

MEDIUM 6.5

DescriptionNVD

Update: On November 5, 2025, Cisco became aware of a new attack variant against devices running Cisco Secure ASA Software or Cisco Secure FTD Software releases that are affected by CVE-2025-20333 and CVE-2025-20362. This attack can cause unpatched devices to unexpectedly reload, leading to denial of service (DoS) conditions. Cisco strongly recommends that all customers upgrade to the fixed software releases that are listed in the Fixed Software ["#fs"] section of this advisory. A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to access restricted URL endpoints that are related to remote access VPN that should otherwise be inaccessible without authentication. This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web server on a device. A successful exploit could allow the attacker to access a restricted URL without authentication.

AnalysisAI

Unauthenticated remote access to restricted VPN web server endpoints in Cisco Secure ASA and Firepower Threat Defense (FTD) software exposes internal VPN-related URLs that require no credentials to reach, due to improper HTTP(S) input validation (CWE-862 - Missing Authorization). Confirmed actively exploited (CISA KEV), with a publicly available proof-of-concept and EPSS at the 97th percentile, making this a high-priority threat for any organization running remote-access VPN on ASA or FTD hardware. A related attack variant - disclosed November 5, 2025, and intersecting with CVE-2025-20333 - can additionally trigger unexpected device reloads on unpatched appliances, compounding the risk with a denial-of-service impact that brings the availability score to High.

Technical ContextAI

Cisco Secure Firewall ASA (Adaptive Security Appliance) Software and Cisco Secure Firewall Threat Defense (FTD) Software - formerly Firepower Threat Defense - are the dominant Cisco perimeter firewall/VPN platforms, identified in CPE as cpe:2.3:o:cisco:adaptive_security_appliance_software and cpe:2.3:a:cisco:firepower_threat_defense. The vulnerable component is the VPN web server, which handles HTTP(S) requests for remote-access VPN (RA-VPN) portal and tunnel endpoints. CWE-862 (Missing Authorization) is the root cause: the server fails to enforce access controls on certain URL paths before processing the request, meaning the authorization gate is simply absent rather than bypassable via a logic flaw. HTTP request routing in ASA/FTD's WebVPN stack does not correctly validate that a URL endpoint requires authentication before serving a response, allowing crafted HTTP(S) requests to reach restricted endpoint handlers. The November 2025 attack variant leverages the same surface in conjunction with CVE-2025-20333 to cause process crashes and device reloads.

RemediationAI

The primary remediation is upgrading to a fixed ASA or FTD software release as specified in the Cisco Security Advisory at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-webvpn-YROOTUW - Cisco strongly recommends all customers apply the fix immediately given active exploitation. Exact fixed version numbers are not independently confirmed in this data set beyond the advisory reference; retrieve them directly from the advisory's Fixed Software table. For organizations unable to patch immediately, a compensating control is to disable the WebVPN/remote-access VPN portal service on the affected interface if RA-VPN is not operationally required, which eliminates the attack surface entirely but also removes VPN access for users. Where RA-VPN must remain active, restrict access to the WebVPN listener to known source IP ranges using ASA interface access-lists or upstream network controls - this does not eliminate the vulnerability but significantly reduces exposure to opportunistic attackers. Note that the November 2025 update (https://sec.cloudapps.cisco.com/security/center/resources/asa_ftd_continued_attacks) indicates that both CVE-2025-20362 and CVE-2025-20333 must be patched together to address the DoS reload variant; patching only one leaves residual risk from the combined attack chain.