The vulnerabilities can be exploited to cause the web visualization component of the PLC to stop and not respond, leading to genuine users losing remote visibility of the PLC state. If a user attempts to login to the PLC while this vulnerability is exploited, the PLC will show an error state and refuse connections to Automation Builder. The execution of the PLC application is not affected by this vulnerability. This issue affects ABB AC500 V2 products with onboard Ethernet.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Pm554_firmware | Abb | - (including) | - (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.