Siemens initially used a relatively simple XOR-based hash to store the project password in the PLC’s EEPROM. Later firmware versions (V02.05+) improved security, but many industrial machines still run older firmware.
Mia’s technique was not a software crack. It was a voltage glitch. siemens s7 200 smart password unlock
Requires a password for uploading or downloading any program blocks. Level 4 (Maximum Protection): Siemens initially used a relatively simple XOR-based hash