CVE-2025-20243: Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerability

Published Aug 14, 2025
·
Updated

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 Software

2 affected components
Cisco Secure Firewall ASA Software
Cisco Secure FTD Software

Event History

Aug 14, 2025
CVE Published
via MITRE·04:29 PM
Data Sourced
via MITRE·04:29 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:15 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What is the severity of CVE-2025-20243?

CVE-2025-20243 has been assigned a significant severity level due to the potential remote denial-of-service (DoS) condition it can cause.

2

How do I fix CVE-2025-20243?

To mitigate CVE-2025-20243, update Cisco Secure Firewall ASA Software and Secure FTD Software to the latest patched version provided by Cisco.

3

What impact does CVE-2025-20243 have on Cisco devices?

CVE-2025-20243 can lead to an unexpected device reload, causing a denial-of-service (DoS) condition that affects device availability.

4

Who is affected by CVE-2025-20243?

Organizations using Cisco Secure Firewall ASA Software or Secure FTD Software are primarily affected by CVE-2025-20243.

5

Is there a workaround for CVE-2025-20243?

Currently, there are no specific workarounds for CVE-2025-20243; upgrading to the latest software is the recommended approach.

Contact

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