BrightSign - Multiple Vulnerablities - CVE-2017-17737, 17738, 17739

The BrightSign Digital Signage (4k242) device (Firmware 6.2.63 and below) suffers from multiple vulnerabilities.

The pages:

/network_diagnostics.html
/storage_info.html

Suffer from a Cross-Site Scripting vulnerability. The REF parameter for these pages do not sanitize user input, resulting in arbitrary execution, token theft and related attacks.



The RP parameter in STORAGE.HTML suffers from a directory traversal/information leakage weakness:
/storage.html?rp=%2E%2E%2F%2E%2E%2F%2E%2E%2F%2E%2E%2F%2E%2E%2F%2E%2E%2F%2E%2E%2Fetc

Through parameter manipulation, the file system can be traversed, unauthenticated, allowing for leakage of information and compromise of the device.

This page also allows for unauthenticated upload of files.

/tools.html

Page allows for unauthenticated rename/manipulation of files.

When combined, these vulnerabilities allow for compromise of both end users and the device itself.

Ex. A malicious attacker can upload a malicious page of their choosing and steal credentials, host malicious content or distribute content through the device, which accepts large format SD cards.