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.
| Software | From | Fixed in |
|---|---|---|
yt-dlp
|
- | 2023.7.06 |
| yt-dlp_project / yt-dlp | - | 2023.07.06.185519 |
| yt-dlp_project / yt-dlp | - | 2023.07.06 |
| youtube-dlc_project / youtube-dlc | - | - |
| yt-dl / youtube-dl | 2015.01.25 | 2015.01.25.x |
| fedoraproject / fedora | 37 | 37.x |
| fedoraproject / fedora | 38 | 38.x |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
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