Package Instance

`yt-dlp` and `youtube-dl` are command-line audio/video downloaders. Prior to the fixed versions, `yt-dlp` and `youtube-dl` do not limit the extensions of downloaded files, which could lead to arbitrary filenames being created in the download folder (and path traversal on Windows). Since `yt-dlp` and `youtube-dl` also read config from the working directory (and on Windows executables will be executed from the `yt-dlp` or `youtube-dl` directory), this could lead to arbitrary code being executed.




`yt-dlp` version 2024.07.01 fixes this issue by whitelisting the allowed extensions. `youtube-dl` fixes this issue in commit `d42a222` on the `master` branch and in nightly builds tagged 2024-07-03 or later. This might mean some very uncommon extensions might not get downloaded, however it will also limit the possible exploitation surface. In addition to upgrading, have `.%(ext)s` at the end of the output template and make sure the user trusts the websites that they are downloading from. Also, make sure to never download to a directory within PATH or other sensitive locations like one's user directory, `system32`, or other binaries locations. For users who are not able to upgrade, keep the default output template (`-o "%(title)s [%(id)s].%(ext)s`); make sure the extension of the media to download is a common video/audio/sub/... one; try to avoid the generic extractor; and/or use `--ignore-config --config-location ...` to not load config from common locations.

yt-dlp is a command-line program to download videos from video sites. During file downloads, yt-dlp or the external downloaders that yt-dlp employs may leak cookies on HTTP redirects to a different host, or leak them when the host for download fragments differs from their parent manifest's host. This vulnerable behavior is present in yt-dlp prior to 2023.07.06 and nightly 2023.07.06.185519. All native and external downloaders are affected, except for `curl` and `httpie` (version 3.1.0 or later).

At the file download stage, all cookies are passed by yt-dlp to the file downloader as a `Cookie` header, thereby losing their scope. This also occurs in yt-dlp's info JSON output, which may be used by external tools. As a result, the downloader or external tool may indiscriminately send cookies with requests to domains or paths for which the cookies are not scoped.

yt-dlp version 2023.07.06 and nightly 2023.07.06.185519 fix this issue by removing the `Cookie` header upon HTTP redirects; having native downloaders calculate the `Cookie` header from the cookiejar, utilizing external downloaders' built-in support for cookies instead of passing them as header arguments, disabling HTTP redirectiong if the external downloader does not have proper cookie support, processing cookies passed as HTTP headers to limit their scope, and having a separate field for cookies in the info dict storing more information about scoping

Some workarounds are available for those who are unable to upgrade. Avoid using cookies and user authentication methods. While extractors may set custom cookies, these usually do not contain sensitive information. Alternatively, avoid using `--load-info-json`. Or, if authentication is a must: verify the integrity of download links from unknown sources in browser (including redirects) before passing them to yt-dlp; use `curl` as external downloader, since it is not impacted; and/or avoid fragmented formats such as HLS/m3u8, DASH/mpd and ISM.