Mitsubishi MELSEC iQ-R Series PLCs with firmware 33 allow attackers to halt the industrial process by sending an unauthenticated crafted packet over the network, because this denial of service attack consumes excessive CPU time. After halting, physical access to the PLC is required in order to restore production.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Melsec_iq-r00cpu_firmware | Mitsubishielectric | * | 7 (including) |
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.