Implementing a secure access feature would ideally reduce $P(\textunauthorized access)$ significantly.
passwords points toward historical, third-party software tools designed to retrieve or bypass forgotten passwords. Official Siemens documentation confirms that there are for recovering forgotten passwords; the only authorized remedy for a lost password is a full factory reset (MRES), which erases all user program data. Overview of Historical Password Tools
If the password is lost and recovery tools are unavailable, the standard procedure is to perform a factory reset, which deletes the protected program and password to allow for a fresh download.
: For some pre-2009 S7-300 versions, the default password is often reported as Basisk . Modern Official Reset Procedures