If you have access to STEP 7 Micro/ Win or STEP 7 Manager, you can use these tools to reset the password.
: Power off, remove the card, and power back on. Your CPU is now back to factory defaults with no password, ready for a fresh download. Alternative: Factory Reset via TIA Portal s71200 password unlock work
This is the official Siemens procedure for recovering a CPU when the password is lost. : If you have access to STEP 7 Micro/
If you are writing a security research paper for an academic or industrial conference (e.g., ICS security), you must include a responsible disclosure statement and proof that you had permission from Siemens or a legal testing lab. Otherwise, the paper would be rejected or could expose you to legal liability. remove the card