The version of FortiWeb installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the FG-IR-21-180 advisory.

– An improper neutralization of special elements used in an OS command (‘OS Command Injection’) vulnerability [CWE-78] in FortiWeb may allow an authenticated attacker to execute arbitrary code or commands via crafted HTTP requests to ApplicationDelivery, JsonProtection and WebProtection controllers.
(CVE-2021-43073)

Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.Read More