Fireshare facilitates self-hosted media and link sharing. Versions 1.2.30 and below allow an authenticated user, or unauthenticated user if the Public Uploads setting is enabled, to craft a malicious filename when uploading a video file. The malicious filename is then concatenated directly into a shell command, which can be used for uploading files to arbitrary directories via path traversal, or executing system commands for Remote Code Execution (RCE). This issue is fixed in version 1.3.0.