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 a

Severity
Critical 9.9
CVSS 3.1
Remote, needs privileges or user interaction what this means
Exploited
Yes — in CISA KEV
Added Sep 25, 2025
EPSS
0.707
99.4th percentile
Discovered by
Third party
Vendor-published field
Published
Sep 25, 2025
Assigned by cisco

Description

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.

Weakness: CWE-120

Affected products

Vendor Product Category Matched by
Cisco Cisco Adaptive Security Appliance (ASA) Check your version Firewall / NGFW cna-assigner
Cisco Cisco Firepower Threat Defense (FTD) Check your version Firewall / NGFW cna-assigner
Vendor-reported products (2)
  • Cisco · Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
  • Cisco · Cisco Secure Firewall Threat Defense (FTD) Software

Vendor advisory

cisco-sa-asaftd-webvpn-z5xP8EUB

Cisco Secure Firewall Adaptive Security Appliance Software and Secure Firewall Threat Defense Software VPN Web Server Remote Code Execution Vulnerability

Cisco’s rating: Critical (advisory CVSS 9.9) · Published Sep 25, 2025 · updated Nov 6, 2025 (revision 2.1)

Bug ID: CSCwq79831

The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from

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