Stand alone messaging gateway scanner password needs to be recovered.
Messaging Gateway 10.7.x
Command line admin accounts cannot be retrieved from stand-alone scanners, there's no back door into a scanner.
If the admin account is lost, the scanner must be restored.
The Control Center has all the configurations for a scanner, it's designed to be quickly rebuilt if necessary. The Message Audit Log will not be retained in this case.
The Control Center password can be reset if the password recovery option is enabled. Ref: https://knowledge.broadcom.com/external/article/177987