A Denial of service (DoS) vulnerability in FortiClient for Linux 6.2.1 and below may allow an user with low privilege to cause FortiClient processes running under root privilege crashes via sending specially crafted IPC client requests to the fctsched process due the nanomsg not been correctly validated.

A stack buffer overflow vulnerability in FortiClient for Linux 6.2.1 and below may allow a user with low privilege to cause FortiClient processes running under root priviledge crashes via sending specially crafted "StartAvCustomScan" type IPC client requests to the fctsched process due the argv data not been well sanitized.

Use of a hardcoded cryptographic key in the FortiGuard services communication protocol may allow a Man in the middle with knowledge of the key to eavesdrop on and modify information (URL/SPAM services in FortiOS 5.6, and URL/SPAM/AV services in FortiOS 6.0.; URL rating in FortiClient) sent and received from Fortiguard severs by decrypting these messages. Affected products include FortiClient for Windows 6.0.6 and below, FortiOS 6.0.7 and below, FortiClient for Mac OS 6.2.1 and below.