Streambert: Local File Exfiltration and Overwrite via Subtitle file: Protocol

Streambert is a cross-platform Electron Desktop App to stream and download video content. Prior to 2.5.0, the downloadSubtitleFile utility in src/ipc/downloads.js, reached through the run-download IPC channel, accepts a renderer-supplied subtitle url using the file: URI scheme and passes its decoded pathname to fs.copyFileSync. The renderer also controls downloadPath, which determines the destination path. A compromised renderer can therefore copy any file readable by the StreamBERT process into an attacker-chosen writable location, exposing sensitive local data, and can overwrite existing writable files. This vulnerability is fixed in 2.5.0.