--- title: "CVE-2023-40581\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2023-40581?format=md keywords: index, follow --- # CVE-2023-40581 Publication date 25 September 2023 Last updated 26 August 2025 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **7.8 · High** [Score breakdown](https://ubuntu.com/security/CVE-2023-40581?format=md#impact-score) Toggle side navigation ## Description yt-dlp is a youtube-dl fork with additional features and fixes. yt-dlp allows the user to provide shell command lines to be executed at various stages in its download steps through the `--exec` flag. This flag allows output template expansion in its argument, so that metadata values may be used in the shell commands. The metadata fields can be combined with the `%q` conversion, which is intended to quote/escape these values so they can be safely passed to the shell. However, the escaping used for `cmd` (the shell used by Python's `subprocess` on Windows) does not properly escape special characters, which can allow for remote code execution if `--exec` is used directly with maliciously crafted remote data. This vulnerability only impacts `yt-dlp` on Windows, and the vulnerability is present regardless of whether `yt-dlp` is run from `cmd` or from `PowerShell`. Support for output template expansion in `--exec`, along with this vulnerable behavior, was added to `yt-dlp` in version 2021.04.11. yt-dlp version 2023.09.24 fixes this issue by properly escaping each special character. `\n` will be replaced by `\r` as no way of escaping it has been found. It is recommended to upgrade yt-dlp to version 2023.09.24 as soon as possible. Also, always be careful when using --exec, because while this specific vulnerability has been patched, using unvalidated input in shell commands is inherently dangerous. For Windows users who are not able to upgrade: 1. Avoid using any output template expansion in --exec other than {} (filepath). 2. If expansion in --exec is needed, verify the fields you are using do not contain ", | or &. 3. Instead of using --exec, write the info json and load the fields from it instead. [Read the notes from the security team](https://ubuntu.com/security/CVE-2023-40581?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | yt-dlp | 23.10 mantic | Not affected | | 23.04 lunar | Not affected | | 22.04 LTS jammy | Not affected | | 20.04 LTS focal | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) ## Notes --- ### [rodrigo-zaiden](https://launchpad.net/~rodrigo-zaiden) issue affects Windows only ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 7.8 · High * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Local | | Attack complexity | Low | | Privileges required | None | | User interaction | Required | | Scope | Unchanged | | Confidentiality impact | High | | Integrity impact | High | | Availability impact | High | * Scores | Parameter | Value | | --- | --- | | Base score | 7.8 · High | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-40581) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2023-40581) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2023-40581) * [Debian](https://security-tracker.debian.org/tracker/CVE-2023-40581) ### Other references * * * * * *