In Slican telephone exchanges secure key is generated in a predictable manner using properties of the telephone exchange which can be obtained without authentication. An unauthenticated attacker can deduce the secure key and obtain admin credentials.
This issue was fixed in versions below:
The issue STILL EXISTS in End-Of-Life telephone exchanges in versions 4.xx and below:
Exploitability
AV:NAC:LAT:NPR:NUI:NVulnerable System
VC:HVI:NVA:NSubsequent System
SC:NSI:NSA:N8.7/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NOther