CVE-2023-40581
highpriority · track · 31EPSS 0.013 · 71 %ileEURUUSEPSS · scored 2026-10-28
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (6)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-42h4-v29r-42qg yt-dlp on Windows vulnerable to `--exec` command injection when using `%q`2023-09-25ghsa · osvUS
### Impact [`yt-dlp`](https://github.com/yt-dlp/yt-dlp) allows the user to provide shell commands to be executed at various stages in its download process through the `--exec` flag. This flag allows output template expansion in its argument, so that video 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) did 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](https://github.com/yt-dlp/yt-dlp/releases/tag/2021.04.11). ```shell > yt-dlp https://youtu.be/Jo66yyCpHcQ --exec "echo %(title)q" [youtube] Extracting URL: https://youtu.be/Jo66yyCpHcQ [youtube] Jo66yyCpHcQ: Downloading webpage [youtube] Jo66yyCpHcQ: Downloading ios player API JSON [youtube] Jo66yyCpHcQ: Downloading android player API JSON [youtube] Jo66yyCpHcQ: Downloading m3u8 information [info] Jo66yyCpHcQ: Downloading 1 format(s): 135+251 [download] Destination: ＂&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f135.mp4 [download] 100% of 4.85KiB in 00:00:00 at 60.20KiB/s [download] Destination: ＂&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f251.webm [download] 100% of 4.80KiB in 00:00:00 at 31.58KiB/s [Merger] Merging formats into "＂&echo(&echo(pwned&rem( [Jo66yyCpHcQ].mkv" Deleting original file ＂&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f135.mp4 (pass -k to keep) Deleting original file ＂&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f251.webm (pass -k to keep) [Exec] Executing command: echo "\"&echo(&echo(pwned&rem(" "\" pwned ``` ### Patches 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. ### Workarounds 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: - Avoid using any output template expansion in `--exec` other than `{}` (filepath). - If expansion in `--exec` is needed, verify the fields you are using do not contain `"`, `|` or `&`. - Instead of using `--exec`, write the info json and load the fields from it instead. ### References - https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-42h4-v29r-42qg - https://nvd.nist.gov/vuln/detail/CVE-2023-40581 - https://github.com/yt-dlp/yt-dlp/releases/tag/2023.09.24 - https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/tag/2023.09.24.003044 - https://github.com/yt-dlp/yt-dlp/commit/de015e930747165dbb8fcd360f8775fd973b7d6e
- PYSEC-2026-2064 yt-dlp on Windows vulnerable to `--exec` command injection when using `%q`2026-07-07vendor · osvUS
### Impact [`yt-dlp`](https://github.com/yt-dlp/yt-dlp) allows the user to provide shell commands to be executed at various stages in its download process through the `--exec` flag. This flag allows output template expansion in its argument, so that video 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) did 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](https://github.com/yt-dlp/yt-dlp/releases/tag/2021.04.11). ```shell > yt-dlp https://youtu.be/Jo66yyCpHcQ --exec "echo %(title)q" [youtube] Extracting URL: https://youtu.be/Jo66yyCpHcQ [youtube] Jo66yyCpHcQ: Downloading webpage [youtube] Jo66yyCpHcQ: Downloading ios player API JSON [youtube] Jo66yyCpHcQ: Downloading android player API JSON [youtube] Jo66yyCpHcQ: Downloading m3u8 information [info] Jo66yyCpHcQ: Downloading 1 format(s): 135+251 [download] Destination: ＂&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f135.mp4 [download] 100% of 4.85KiB in 00:00:00 at 60.20KiB/s [download] Destination: ＂&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f251.webm [download] 100% of 4.80KiB in 00:00:00 at 31.58KiB/s [Merger] Merging formats into "＂&echo(&echo(pwned&rem( [Jo66yyCpHcQ].mkv" Deleting original file ＂&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f135.mp4 (pass -k to keep) Deleting original file ＂&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f251.webm (pass -k to keep) [Exec] Executing command: echo "\"&echo(&echo(pwned&rem(" "\" pwned ``` ### Patches 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. ### Workarounds 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: - Avoid using any output template expansion in `--exec` other than `{}` (filepath). - If expansion in `--exec` is needed, verify the fields you are using do not contain `"`, `|` or `&`. - Instead of using `--exec`, write the info json and load the fields from it instead. ### References - https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-42h4-v29r-42qg - https://nvd.nist.gov/vuln/detail/CVE-2023-40581 - https://github.com/yt-dlp/yt-dlp/releases/tag/2023.09.24 - https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/tag/2023.09.24.003044 - https://github.com/yt-dlp/yt-dlp/commit/de015e930747165dbb8fcd360f8775fd973b7d6e
also known as (7)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (16)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2023-40581/cnnvd
- https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/tag/2023.09.24.003044cnnvd
- https://github.com/yt-dlp/yt-dlp/commit/de015e930747165dbb8fcd360f8775fd973b7d6ecnnvd
- https://github.com/yt-dlp/yt-dlp/releases/tag/2021.04.11cnnvd
- https://github.com/yt-dlp/yt-dlp/releases/tag/2023.09.24cnnvd
- https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-42h4-v29r-42qgcnnvd
- https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/tag/2023.09.24.003044enisa_euvd
- https://github.com/yt-dlp/yt-dlp/commit/de015e930747165dbb8fcd360f8775fd973b7d6eenisa_euvd
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