In Mitsubishi Electric MELSEC-Q Series Q03/04/06/13/26UDVCPU: serial number 21081 and prior, Q04/06/13/26UDPVCPU: serial number 21081 and prior, and Q03UDECPU, Q04/06/10/13/20/26/50/100UDEHCPU: serial number 21081 and prior, MELSEC-L Series L02/06/26CPU, L26CPU-BT: serial number 21101 and prior, L02/06/26CPU-P, L26CPU-PBT: serial number 21101 and prior, and L02/06/26CPU-CM, L26CPU-BT-CM: serial number 21101 and prior, a remote attacker can cause the FTP service to enter a denial-of-service condition dependent on the timing at which a remote attacker connects to the FTP server on the above CPU modules.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Q03/04/06/13/26udvcpu_firmware | Mitsubishielectric | * | 21081 (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.