ABB Cylon Aspect 3.08.01 (bigUpload.php) Remote Code Execution

The ABB BMS/BAS controller suffers from a remote code execution vulnerability. The vulnerable uploadFile() function in bigUpload.php improperly reads raw POST data using the php://input wrapper without sufficient validation. This data is passed to the fwrite() function, allowing arbitrary file writes. Combined with an improper sanitization of file paths, this leads to directory traversal, allowing an attacker to upload malicious files to arbitrary locations. Once a malicious file is written to an executable directory, an authenticated attacker can trigger the file to execute code and gain unauthorized access to the building controller.