CVE-2025-20333

CVE Enrichment

CVSS: 9.9 CRITICAL
EPSS: 70.65%
EPSS Percentile: 99.38%
CISA KEV: YES — Known Exploited Vulnerability

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.

Technical Details

CVSS Version: 3.1
CNA / NVD Source: psirt@cisco.com
Published: 25-Sep-2025 23:15
Last Modified: 12-Aug-2026 02:33
EPSS Date: 2026-10-10
CWE: CWE-120

CVSS Vector


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

CISA KEV Details

Date Added: 2025-09-25
Remediation Due: 2025-09-26
Known Ransomware Campaign Use: Unknown
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.
Notes: CISA Mitigation Instructions: https://www.cisa.gov/news-events/directives/ed-25-03-identify-and-mitigate-potential-compromise-cisco-devices ; https://www.cisa.gov/news-events/directives/supplemental-direction-ed-25-03-core-dump-and-hunt-instructions ; https://www.cisa.gov/eviction-strategies-tool/create-from-template ; https://sec.cloudapps.cisco.com/security/center/resources/asa_ftd_continued_attacks ; https://sec.cloudapps.cisco.com/security/center/private/resources/asa_ftd_continued_attacks#Details ; https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-webvpn-z5xP8EUB ; https://nvd.nist.gov/vuln/detail/CVE-2025-20333

Affected Products / Versions

cisco / adaptive_security_appliance_software
Version / affected range: * · from (inclusive) 9.12 · before (exclusive) 9.12.4.72
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco / adaptive_security_appliance_software
Version / affected range: * · from (inclusive) 9.14 · before (exclusive) 9.14.4.28
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco / adaptive_security_appliance_software
Version / affected range: * · from (inclusive) 9.16 · before (exclusive) 9.16.4.85
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco / adaptive_security_appliance_software
Version / affected range: * · from (inclusive) 9.17.0 · before (exclusive) 9.17.1.45
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco / adaptive_security_appliance_software
Version / affected range: * · from (inclusive) 9.18 · before (exclusive) 9.18.4.47
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco / adaptive_security_appliance_software
Version / affected range: * · from (inclusive) 9.19 · before (exclusive) 9.19.1.37
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco / adaptive_security_appliance_software
Version / affected range: * · from (inclusive) 9.20 · before (exclusive) 9.20.3.7
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco / adaptive_security_appliance_software
Version / affected range: * · from (inclusive) 9.22 · before (exclusive) 9.22.1.3
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco / secure_firewall_threat_defense
Version / affected range: * · from (inclusive) 7.0.0 · before (exclusive) 7.0.8.1
cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
cisco / secure_firewall_threat_defense
Version / affected range: * · from (inclusive) 7.1.0 · before (exclusive) 7.2.9
cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
cisco / secure_firewall_threat_defense
Version / affected range: * · from (inclusive) 7.3.0 · before (exclusive) 7.4.2.4
cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
cisco / secure_firewall_threat_defense
Version / affected range: 7.6.0
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.6.0:*:*:*:*:*:*:*

References

Last enrichment sync: 11-Oct-2026 11:24
Sources: NVD · FIRST EPSS · CISA KEV
Latest successful provider update; providers refresh independently.

Reported Context (2)

devices’ Firepower eXtensible Operating System (FXOS). UAT-4356 exploited n-day vulnerabilities (CVE-2025-20333 and CVE-2025-20362) to gain unauthorized access to vulnerable devices, where the threat actor UAT-4356 Uses FIRESTARTER Backdoor to Target Cisco Firepower Devices
Adaptive Security Appliances (ASA) 5500-X Series and has released three CVE’s related to the event: CVE-2025-20333, CVE-2025-20362 and CVE-2025-20363. The following Snort Rules cover these vulnerabilities: 65340, Cisco Details ArcaneDoor Espionage Campaign Targeting Perimeter Devices

CVE (5)

Malware (3)

Threat Actors (3)

MITRE ATT&CK (16)

Vendors (2)

Products (15)

Tools (2)

Industries (2)

Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.