Fortinet FortiClient is a mobile endpoint security solution from Fortinet, a US-based company. The solution provides IPsec and SSL encryption, WAN optimization, endpoint compliance, and two-factor authentication when connected to a FortiGate firewall appliance.Fortinet FortiClient has a security vulnerability that could be exploited by an attacker to act as a man-in-the-middle on FortiClient via the telemetry protocol in order to read or write data in a session. Data.