Fortinet FortiClient is a fabric agent from Fortinet USA, Inc. It is used to provide protection, compliance and secure access in a single modular lightweight client.Fortinet FortiClient for Windows 7.0.0, versions 6.4.6 and earlier and 6.2.8 and earlier are vulnerable to an authorization error. An unauthenticated attacker could exploit the vulnerability to bypass webfilter controls by modifying the session-id parameter.