youtube-dl vulnerable to file system modification and RCE through improper file-extension sanitization
#### Description This advisory follows the security advisory [GHSA-79w7-vh3h-8g4j published by the _yt-dlp/yt-dlp_ project](https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-79w7-vh3h-8g4j) to aid remediation of the issue in the _ytdl-org/youtube-dl_ project. ### Vulnerability _youtube-dl_ does not limit the extensions of downloaded files, which could lead to arbitrary filenames being created in the download folder (and path traversal on Windows). ### Impact Since _youtube-dl_ also reads config from the working directory (and, on Windows, executables will be executed from the _youtube-dl_ directory by default) the vulnerability cou