CVE-2025-20333
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.
Fix
Public exploits 3
- cobbbex/Cisco-ASA-vulnerability-research PoC on GitHub
- cobbbex/cve-2025-20333 PoC on GitHub
- curtishoughton/Cisco-ASA-CVE-2025-20333-Scanner PoC on GitHub
Each line links to the index that lists it, never to exploit code. Exploit-DB's "verified" and a Metasploit rank of good or better count as verified; a PoC-in-GitHub entry is a repository's claim.
CISA KEV required action · due 2025-09-26
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.
Added to the catalog 2025-09-25. CISA KEV
Patch, vendor advisory and mitigation references on NVD 2
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-webvpn-z5xP8EUB Vendor Advisory
- https://sec.cloudapps.cisco.com/security/center/resources/asa_ftd_continued_attacks Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 9.9 · in KEV · ciscoNVD modified 2026-10-18 21:10
Affected (CPE criteria) 3
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.6.0:*:*:*:*:*:*:*
References 3
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-webvpn-z5xP8EUB Vendor Advisory
- https://sec.cloudapps.cisco.com/security/center/resources/asa_ftd_continued_attacks Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-20333 US Government Resource