描述
KAYSUS KS-WR3600 routers with firmware 1.0.5.9.1 allow authentication bypass during session validation. If any user is logged in, endpoints such as /cgi-bin/system-tool accept unauthenticated requests with empty or invalid session values. This design flaw lets attackers piggyback on another user's active session to retrieve sensitive configuration data or execute privileged actions without authentication.