# CVE-2023-35934: yt-dlp File Downloader cookie leak > Attackers can steal session cookies via HTTP redirects or fragmented downloads, potentially leading to account takeover. - **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 6 Jul 2023 - **Updated:** 13 Feb 2025 - **Also known as:** DEBIAN-CVE-2023-35934, GHSA-v8mc-9377-rwjj, PYSEC-2026-2067, UBUNTU-CVE-2023-35934, openSUSE-SU-2024:13142-1 ## What is CVE-2023-35934? CVE-2023-35934 is a medium-severity vulnerability in Fedoraproject Fedora, published on 6 Jul 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. ### Official description 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. Weakness: CWE-601 (URL Redirection to Untrusted Site), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) ## Which versions are affected by CVE-2023-35934? 3 open source packages ship an affected version, including yt-dlp. It affects 4 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `yt-dlp` | PyPI | All versions | 2023.7.06 | | `yt-dlp` | PyPI | All versions | 2023.7.06 | | `yt-dlp` | PyPI | All versions | 2023.7.06 | | `yt-dlp` | openSUSE:Tumbleweed | All versions | 2023.07.06-1.1 | Products: Fedoraproject Fedora, Youtube-Dlc Project Youtube-Dlc, Yt-Dl Youtube-Dl, Yt-Dlp Project Yt-Dlp. ## How do I fix CVE-2023-35934? Upgrade yt-dlp to 2023.7.06 or later. ## Is CVE-2023-35934 being exploited? There is no known exploitation of CVE-2023-35934 in the wild and no public exploit code. ## Other vulnerabilities in Fedoraproject Fedora - [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild) - [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild) - [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild) - [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild) - [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2023-35934 and fix it if it is affected. What it is: CVE-2023-35934 is a medium-severity vulnerability in Fedoraproject Fedora, published on 6 Jul 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. Exploitation: There is no known exploitation of CVE-2023-35934 in the wild and no public exploit code. Affected packages and fixed versions: - yt-dlp (PyPI): affected all versions; fixed in 2023.7.06 - yt-dlp (PyPI): affected all versions; fixed in 2023.7.06 - yt-dlp (PyPI): affected all versions; fixed in 2023.7.06 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2023-35934/ (Markdown: https://insights.sbomify.com/CVE-2023-35934/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2023-35934 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-35934 - OSV: https://osv.dev/vulnerability/CVE-2023-35934 --- From sbomify Insights: https://insights.sbomify.com/CVE-2023-35934/ Summaries are generated and may contain mistakes; the official description above is the record.