CVE-2025-20333 CRITICAL

CVE-2025-20333

Vendor Cisco
Product Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Weakness CWE-120
KEV Status Known Exploited
Published September 25, 2025
Last update February 26, 2026
View on NVD All CVEs

CVSS base score

9.9/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

What the vulnerability does

01Description

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.

CISA mandated remediation

02CISA Required Action

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.

Key dates

03Disclosure timeline

September 25, 2025 CVE published
February 26, 2026 Record updated

External resources

04References

NVD — National Vulnerability Database https://nvd.nist.gov/vuln/detail/CVE-2025-20333 CWE — Common Weakness Enumeration https://cwe.mitre.org/data/definitions/120.html CISA KEV Reference https://www.cisa.gov/news-events/directives/ed-25-03-identify-… CISA KEV Reference https://www.cisa.gov/news-events/directives/supplemental-direc… CISA KEV Reference https://www.cisa.gov/eviction-strategies-tool/create-from-temp… CISA KEV Reference https://sec.cloudapps.cisco.com/security/center/resources/asa_… CISA KEV Reference https://sec.cloudapps.cisco.com/security/center/private/resour… CISA KEV Reference https://sec.cloudapps.cisco.com/security/center/content/CiscoS… CISA KEV Reference https://nvd.nist.gov/vuln/detail/CVE-2025-20333