In CODESYS Gateway Server V2 an insufficient check for the activity of TCP client connections allows an unauthenticated attacker to consume all available TCP connections and prevent legitimate users or clients from establishing a new connection to the CODESYS Gateway Server V2. Existing connections are not affected and therefore remain intact.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Gateway | Codesys | 2.0 (including) | 2.3.9.38 (excluding) |
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.