CVE-2023-35934

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.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-35934
https://www.cve.org/CVERecord?id=CVE-2023-35934
https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/tag/2023.07.06.185519
https://github.com/yt-dlp/yt-dlp/commit/1ceb657bdd254ad961489e5060f2ccc7d556b729
https://github.com/yt-dlp/yt-dlp/commit/3121512228487c9c690d3d39bfd2579addf96e07
https://github.com/yt-dlp/yt-dlp/commit/f8b4bcc0a791274223723488bfbfc23ea3276641
https://github.com/yt-dlp/yt-dlp/releases/tag/2023.07.06
https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-v8mc-9377-rwjj