An unused function in MicroServer can start a reverse SSH connection to a vendor registered domain, without mutual authentication. An attacker on the local network with admin access to the web server, and the ability to manipulate DNS responses, can redirect the SSH connection to an attacker controlled device.
Exploitability
AV:NAC:LAT:NPR:LUI:NVulnerable System
VC:HVI:HVA:HSubsequent System
SC:NSI:NSA:N8.7/CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NOther