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.