Cross-site request forgery (CSRF) vulnerability in MAHO-PBX NetDevancer Lite/Uni/Pro/Cloud prior to Ver.1.11.00, MAHO-PBX NetDevancer VSG Lite/Uni prior to Ver.1.11.00, and MAHO-PBX NetDevancer MobileGate Home/Office prior to Ver.1.11.00 allows a remote unauthenticated attacker to hijack the user authentication and conduct user's unintended operations by having a user to view a malicious page while logged in.