Nortek Linear eMerge E3-Series devices through 0.32-09c place admin credentials in /test.txt that allow an attacker to open a building's doors. (This occurs in situations where the CVE-2019-7271 default credentials have been changed.)
https://www.nortekcontrol.com/access-control/
https://gist.github.com/omarhashem123/71ec9223e90ea76a76096d777d9b945c