The Relish (Verve Connect) VH510 device with firmware before 1.0.1.6L0516 contains undocumented default admin credentials for the web management interface. A remote attacker could exploit this vulnerability to login and execute commands on the device, as well as upgrade the firmware image to a malicious version.
https://6point6.co.uk/wp-content/uploads/2020/10/Relish-4G-VH510-Hub-Full-Disclosure-v1.3.pdf
https://6point6.co.uk/insights/security-advisory-relish-4g-hub-vh510/