BrightSign Digital Signage - Multiple Vulnerablities

# Exploit Title: BrightSign Digital Signage (Multiple Vulnerabilities)
# Date: 12/15/17
# Exploit Author: [email protected]
# Vectors: XSS, Directory Traversal, File Modification, Information Leakage


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.