Auth bypass in Cisco Adaptive Security Appliance Software
CVE-2025-20362
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.
Vulnerability class: Broken Access Control
EPSS: 0.871 (99.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
Affected products
- Cisco Adaptive_security_appliance_software
- Cisco Secure Firewall Adaptive Security Appliance (Asa) Software — versions 9.8.1, 9.8.1.5, 9.8.1.7
- Cisco Secure Firewall Threat Defense (Ftd) Software — versions 6.2.3, 6.2.3.1, 6.2.3.2
- Cisco Firepower_threat_defense
- Cisco Secure_firewall_threat_defense
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
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.
Public proof-of-concept exploits
References
- psirt@cisco.com (Vendor Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Vendor Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2025-20362?
- CVE-2025-20362 is a medium-severity vulnerability in Cisco Adaptive Security Appliance Software, classified under Missing Authorization. CVSS score: 6.5/10. Published 2025-09-25.
- How severe is CVE-2025-20362?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2025-20362 known to be exploited?
- Yes. CVE-2025-20362 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-09-25), indicating it is being actively exploited. 6 public proof-of-concept repositories are indexed.