SaTECH BCU, in its firmware version 2.1.3, could allow XSS attacks and other malicious resources to be stored on the web server. An attacker with some knowledge of the web application could send a malicious request to the victim users. Through this request, the victims would interpret the code (resources) stored on another malicious website owned by the attacker.
The product uses a web-client protection mechanism such as a Content Security Policy (CSP) or cross-domain policy file, but the policy includes untrusted domains with which the web client is allowed to communicate.
If a cross-domain policy file includes domains that should not be trusted, such as when using wildcards under a high-level domain, then the application could be attacked by these untrusted domains. In many cases, the attack can be launched without the victim even being aware of it.