If there were a master password that you could get here, why would Seagate bother to implement password protection?
If you don't need the data, but just want to re-use the drive, it is possible that a "secure erase" would wipe the data but reset the password. Secure erase is implemented in the firmware; look for it online.
If you need the data on it, ask the original owner for the password. If you are the original owner, I hope that you have backups.