CVE-2024-7034: Remote Code Execution due to Arbitrary File Write in open-webui/open-webui

In open-webui version 0.3.8, the endpoint /models/upload is vulnerable to arbitrary file write due to improper handling of user-supplied filenames. The vulnerability arises from the usage of filepath = f"{UPLOADDIR}/{file.filename}" without proper input validation or sanitization. An attacker can exploit this by manipulating the file.filename parameter to include directory traversal sequences, causing the resulting filepath to escape the intended UPLOADDIR and potentially overwrite arbitrary files on the system. This can lead to unauthorized modifications of system binaries, configuration files, or sensitive data, potentially enabling remote command execution.