https://bugzilla.suse.com/show_bug.cgi?id=1215701 Bug ID: 1215701 Summary: VUL-0: CVE-2023-40581: yt-dlp: template expansion in `--exec` flag Classification: openSUSE Product: openSUSE Distribution Version: Leap 15.6 Hardware: Other URL: https://smash.suse.de/issue/379815/ OS: Other Status: NEW Severity: Major Priority: P5 - None Component: Security Assignee: jengelh@inai.de Reporter: smash_bz@suse.de QA Contact: security-team@suse.de CC: rfrohl@suse.com Target Milestone: --- Found By: Security Response Team Blocker: --- 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. References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-40581 -- You are receiving this mail because: You are on the CC list for the bug.