This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Advantech WebAccess. Authentication is not required to exploit this vulnerability.
The specific flaw exists within the WebAccess Dashboard Viewer. Insufficient validation within the uploadImageCommon function in the UploadAjaxAction script allows unauthenticated callers to upload arbitrary code (instead of an image) to the server, which will then be executed under the high-privilege context of the IIS AppPool. An attacker can leverage this vulnerability to execute arbitrary code under the context of SYSTEM.