Product:
Cisco Secure Firewall
Summary
A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance Software and Cisco Secure Firewall Threat Defense Software could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. This vulnerability is due to ineffective memory management of the VPN web server. An attacker could exploit this vulnerability by sending a large number of crafted HTTP requests to an affected device.
Details
| Severity | Base Score | CVE |
|---|---|---|
| HIGH | 8.6 | CVE-2026-20039 |
Exploitation
An attacker can exploit this vulnerability by sending a large volume of specially crafted HTTP requests to the VPN web server of the affected device. If successful, this could lead to the device reloading and ultimately result in a denial of service condition, making the device unavailable to legitimate users.
Affected Products
- Cisco Secure Firewall Adaptive Security Appliance Software: Affected by the vulnerability in its VPN web server, leading to potential denial of service.
- Cisco Secure Firewall Threat Defense Software: Also vulnerable through its VPN web server, which can be exploited similarly.
Mitigation
To mitigate this vulnerability, it is recommended to apply the latest security patches provided by Cisco for the affected products. Additionally, monitoring network traffic for unusual patterns and limiting the number of incoming requests to the VPN web server can help reduce the risk of exploitation.