Improper resource shutdown or release in Cisco Firewall Threat Defense (FTD) and Cisco Adaptive Security Appliance (ASA) - CVE-2025-20127
Published: September 3, 2025
Vulnerability identifier: #VU114759
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-20127
CWE-ID: CWE-404
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to perform a denial of service (DoS) attack.
The vulnerability exists due to incorrect implementation of the TLS 1.3 Cipher TLS_CHACHA20_POLY1305_SHA256. A remote user can force the device to stop accepting any new SSL/TLS or VPN requests, leading to a denial of service.
Affected software
Cisco Firewall Threat Defense (FTD)
Cisco Adaptive Security Appliance (ASA)
Cisco Adaptive Security Appliance (ASA)
How to mitigate CVE-2025-20127
Install updates from vendor's website.
Cisco Firewall Threat Defense (FTD) - addressed in versions 7.4.2.2, 7.6.1
Cisco Adaptive Security Appliance (ASA) - addressed in versions 9.20.3.10, 9.22.1.3, 9.22.2.4
Cisco Adaptive Security Appliance (ASA) - addressed in versions 9.20.3.10, 9.22.1.3, 9.22.2.4