E3 Site Supervisor Control (firmware version < 2.31F01) contains a hidden API call in the application services that enables SSH and Shellinabox, which exist but are disabled by default. An attacker with admin access to the application services can utilize this API to enable remote access to the underlying OS.
Exploitability
AV:NAC:LAT:NPR:HUI:NVulnerable System
VC:NVI:HVA:NSubsequent System
SC:NSI:NSA:N6.9/CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:NOther