Executive brief
A configuration issue exists where standard computers or servers are inadvertently acting as network routers. This allows unauthorized network traffic to pass through the system, potentially bypassing security perimeters or exposing internal network segments. An attacker could use this to reach protected systems that should not be accessible from their location.
Technical details
The system is configured with IP forwarding enabled (e.g., net.ipv4.ip_forward = 1 on Linux), despite not being a dedicated networking device. This configuration allows the host to route packets between different network interfaces or subnets. A remote attacker can leverage this to bypass network access control lists (ACLs) or reach internal network segments that are otherwise isolated. This is a common misconfiguration in multi-homed systems that can lead to unauthorized network traversal. Remediation involves disabling IP forwarding in the operating system kernel settings if routing capabilities are not required for the business function of the host.
Affected products
- Microsoft windows_2000
- Microsoft windows_nt
Timeline
- 1997-01-01: disclosed: NVD Published Date