CVE-2025-20333
Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability
- Published
- Sep 25, 2025
- Updated
- Feb 26, 2026
- Assigning CNA
- cisco
- Evidence observed
- Sep 25, 2025
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HHigh · next 30 days
- Percentile
- 99.4%
- Model date
- Sep 21, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
CISA Known Exploited
This CVE appears in the CISA Known Exploited Vulnerabilities catalog.
Summary
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 authenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests. An attacker with valid VPN user credentials could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to execute arbitrary code as root, possibly resulting in the complete compromise of the affected device.
Sources
2- cve-2025-20333Exploit
Complete research and exploitation toolkit for CVE-2025-20333, a critical stack buffer overflow in Cisco ASA/FTD WebVPN. Includes detailed binary analysis, PoC exploits in Python and bash, and exploitation guide.
Safe Python scanner for Cisco CVE-2025-20333 (Cisco ASA/FTD WebVPN Buffer Overflow)
Responsible use
Use vulnerability information only on systems you own or are authorized to test. Kitploit links to public research metadata and does not store exploit code or malicious payloads.