Product:
Cisco Secure Firewall
Summary
A vulnerability in Cisco Secure Firewall Adaptive Security Appliance Software and Cisco Secure Firewall Threat Defense Software could allow an unauthenticated, remote attacker to send traffic that should be denied through an affected device. This vulnerability is due to improper error handling when an affected device that is joining a cluster runs out of memory while replicating access control rules. A successful exploit could allow the attacker to bypass access controls and reach devices in protected networks.
Details
| Severity | Base Score | CVE |
|---|---|---|
| MEDIUM | 5.8 | CVE-2026-20073 |
Exploitation
An attacker can exploit this vulnerability by sending traffic that should be blocked through the device. This is possible due to improper error handling when the device runs out of memory while replicating access control rules. By leveraging this flaw, the attacker can bypass the intended access controls and gain unauthorized access to protected networks.
Affected Products
- Cisco Secure Firewall Adaptive Security Appliance Software: Vulnerable to traffic bypass due to memory handling issues.
- Cisco Secure Firewall Threat Defense Software: Similar vulnerability allowing unauthorized traffic through the device.
Mitigation
To mitigate this vulnerability, it is recommended to apply the latest patches and updates provided by Cisco. Additionally, monitoring network traffic for unusual patterns and implementing strict access control measures can help reduce the risk of exploitation.