An Improper Access Control vulnerability allows an attacker to access the control panel of the B420 without requiring any sort of authorization or authentication due to the IP based authorization. If an authorized user has accessed a publicly available B420 product using valid credentials, an insider attacker can gain access to the same panel without requiring any sort of authorization. The B420 module was already obsolete at the time this vulnerability was found (The End of Life announcement was made in 2013).
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.