Hi rcmaehl,
Are the randomized password you talk about for the admin panel of the modem because this vulnerability dosen't care about that password it still works. If the spectrum analyzer (a diagnostic tool) is running on your modem you are probably vulnerable.
The spectrum analyzer may be password protected but i is usually a default username and password like spectrum:spectrum or admin:password is used. The spectrum analyzer is usually running on http://192.168.100.1:8080, http://192.168.0.1:8080 or http://192.168.100.1:6080 or something like that.
You can use nmap -p- 192.168.100.1 to port scan or use this tool to check: https://github.com/Lyrebirds/cable-haunt-vulnerability-test.