BrightSign Digital Signage Diagnostic Web Server 8.2.26 and less contains an unauthenticated server-side request forgery vulnerability in the url GET parameter of the Download Speed Test service. Attackers can specify external domains to bypass firewalls and perform network enumeration by forcing the application to make arbitrary HTTP requests to internal network hosts.
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.