Heap-based buffer overflow in Cisco Firewall Threat Defense (FTD) and Cisco Adaptive Security Appliance (ASA) - CVE-2025-20363
Published: September 25, 2025
Vulnerability identifier: #VU116120
CSH Severity: Critical
CVSS v4: 9.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-20363
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error in the web services. A remote attacker can send specially crafted HTTP requests to a targeted web service, trigger a heap-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Affected software
Cisco Firewall Threat Defense (FTD)
Cisco Adaptive Security Appliance (ASA)
Cisco IOS XR
Cisco IOS XE
Cisco Adaptive Security Appliance (ASA)
Cisco IOS XR
Cisco IOS XE
How to mitigate CVE-2025-20363
Install updates from vendor's website.
Cisco Firewall Threat Defense (FTD) - addressed in versions 7.0.8, 7.2.10, 7.4.2.3, 7.6.1, 7.7.10
Cisco Adaptive Security Appliance (ASA) - addressed in versions 9.16.4.84, 9.18.4.57, 9.19.1.42, 9.20.3.16, 9.22.2, 9.23.1.3
Cisco IOS XE - addressed in versions 16.12.14, 17.9.7a, 17.9.8, 17.12.6, 17.15.1z, 17.15.3a, 17.15.4, 17.18.1
Cisco Adaptive Security Appliance (ASA) - addressed in versions 9.16.4.84, 9.18.4.57, 9.19.1.42, 9.20.3.16, 9.22.2, 9.23.1.3
Cisco IOS XE - addressed in versions 16.12.14, 17.9.7a, 17.9.8, 17.12.6, 17.15.1z, 17.15.3a, 17.15.4, 17.18.1