CVE-2025-20243

Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerability

HIGH
8.6
CVSS Score
Published: August 14, 2025 at 04:29 PM UTC
Updated: June 17, 2026 at 08:41 AM UTC
2 products affected across 1 vendorAdaptive Security ApplianceFirepower Threat Defense

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Severity
HIGH8.6
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

Description

A vulnerability in the management and VPN web servers of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a DoS condition. This vulnerability is due to improper validation of user-supplied input on an interface with VPN web services. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web server on an affected device. A successful exploit could allow the attacker to cause a DoS condition when the device reloads.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

9.12.19.12.1.29.12.1.39.12.29.12.2.19.12.2.49.12.2.59.12.2.99.12.39.12.3.129.12.3.29.12.3.79.12.3.99.12.49.12.4.109.12.4.139.12.4.189.12.4.29.12.4.249.12.4.269.12.4.299.12.4.309.12.4.359.12.4.379.12.4.389.12.4.399.12.4.49.12.4.409.12.4.419.12.4.479.12.4.489.12.4.509.12.4.529.12.4.549.12.4.559.12.4.569.12.4.589.12.4.629.12.4.659.12.4.679.12.4.79.12.4.89.14.19.14.1.109.14.1.159.14.1.199.14.1.309.14.1.69.14.29.14.2.139.14.2.159.14.2.49.14.2.89.14.39.14.3.19.14.3.119.14.3.139.14.3.159.14.3.189.14.3.99.14.49.14.4.129.14.4.139.14.4.149.14.4.159.14.4.179.14.4.229.14.4.239.14.4.249.14.4.69.14.4.79.16.19.16.1.289.16.29.16.2.119.16.2.139.16.2.149.16.2.39.16.2.79.16.39.16.3.149.16.3.159.16.3.199.16.3.239.16.3.39.16.49.16.4.149.16.4.189.16.4.199.16.4.279.16.4.389.16.4.399.16.4.429.16.4.489.16.4.559.16.4.579.16.4.619.16.4.629.16.4.679.16.4.709.16.4.719.16.4.769.16.4.829.16.4.99.17.19.17.1.109.17.1.119.17.1.139.17.1.159.17.1.209.17.1.309.17.1.339.17.1.399.17.1.459.17.1.469.17.1.79.17.1.99.18.19.18.1.39.18.29.18.2.59.18.2.79.18.2.89.18.39.18.3.399.18.3.469.18.3.539.18.3.559.18.3.569.18.49.18.4.229.18.4.249.18.4.299.18.4.349.18.4.409.18.4.479.18.4.59.18.4.509.18.4.529.18.4.539.18.4.89.19.19.19.1.129.19.1.189.19.1.229.19.1.249.19.1.279.19.1.289.19.1.319.19.1.379.19.1.389.19.1.59.19.1.99.20.19.20.1.59.20.29.20.2.109.20.2.219.20.2.229.20.39.20.3.109.20.3.139.20.3.49.20.3.79.20.3.99.22.1.19.22.1.29.22.1.39.22.1.69.23.19.8.19.8.1.59.8.1.79.8.29.8.2.149.8.2.159.8.2.179.8.2.209.8.2.249.8.2.269.8.2.289.8.2.339.8.2.359.8.2.389.8.2.459.8.2.89.8.39.8.3.119.8.3.149.8.3.169.8.3.189.8.3.219.8.3.269.8.3.299.8.3.89.8.49.8.4.109.8.4.129.8.4.159.8.4.179.8.4.209.8.4.229.8.4.259.8.4.269.8.4.299.8.4.39.8.4.329.8.4.339.8.4.349.8.4.359.8.4.399.8.4.409.8.4.419.8.4.439.8.4.449.8.4.459.8.4.469.8.4.489.8.4.79.8.4.8

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.6HIGHcisco
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-835

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