Schneider Modicon Ladder Logic Upload/Download

The Schneider Modicon with Unity series of PLCs use Modbus function code 90 0x5a to send and receive ladder logic. The protocol is unauthenticated, and allows a rogue host to retrieve the existing logic and to upload new logic. Two modes are supported: "SEND" and "RECV," which behave as one might...

Ladder logic

The devices tested by the Basecamp Project included the D20 PLC by GE, The Modicon Quantum by Schneider Electric, Rockwell and Koyo Electronics. Each device was tested using a number of additional attack vectors. Researchers attempted to upload custom firmware or so-called “ladder logic” for the...