CVE-2023-40581: Yt dlp Yt-dlp On Windows Vulnerable To Vulnerability

HIGH
Advisory Identifier: GHSA-42h4-v29r-42qg
CVSS 8.3
CWE-78
Published
Advisory Summary

CVE-2023-40581 is a HIGH (CVSS 8.3) yt-dlp on windows vulnerable to vulnerability (CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')) affecting Yt dlp libraries in the PyPI ecosystem. The issue involves yt-dlp on windows vulnerable to `--exec` command injection when using `%q`. Remediation is available by upgrading affected packages to version 2023.09.24.

CVE-2023-40581 at a Glance

CVE Identifier CVE-2023-40581
GHSA Identifier GHSA-42h4-v29r-42qg
Severity HIGH
CVSS v3.1 Base Score 8.3
CWE Classification CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Affected Product Yt dlp
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 8.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2023-40581

To remediate this vulnerability, upgrade all affected Yt dlp dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

yt-dlp fixed: 2023.09.24
pip install yt-dlp>=2023.09.24
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show yt-dlp

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2023-40581, inspect your installed packages using pip:

pip show yt-dlp

Analyze the terminal output to locate any version of Yt dlp in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2023.09.24), your application is affected.

Note: The pip show yt-dlp command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'), where the product constructs all or part of an os command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended os command when it is sent to a downstream component. In Yt dlp, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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

CVE-2023-40581 Affected Yt dlp Versions

1 component(s)
Fixed Versions:
2023.09.24
Product / Package Ecosystem Affected Versions Fixed Version
yt-dlp
PyPI
≥ 2021.04.11
< 2023.09.24
2023.09.24

References

Frequently Asked Questions

What is CVE-2023-40581?
CVE-2023-40581 is a security vulnerability in Yt dlp involving yt-dlp on Windows vulnerable to `--exec` command injection when using `%q` under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection').
Which Yt dlp versions are affected?
Affected versions include releases prior to 2023.09.24 across affected packages: yt-dlp.
What version fixes CVE-2023-40581?
Upgrading to 2023.09.24 (or the latest patched release for your respective branch) resolves the vulnerability.
Is yt-dlp affected?
Yes, yt-dlp is affected in releases prior to 2023.09.24. Upgrade your dependency to 2023.09.24 or later.
What is the CVSS score of CVE-2023-40581?
CVE-2023-40581 has a CVSS v3.1 base score of 8.3 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2023-40581?
CVE-2023-40581 is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') (The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.).
How can I check PyPI dependencies for CVE-2023-40581?
Run the dependency tree command: 'pip show yt-dlp'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-42h4-v29r-42qg",
  "modified" : "2023-09-26T13:57:26Z",
  "published" : "2023-09-25T17:33:40Z",
  "aliases" : [ "CVE-2023-40581" ],
  "summary" : " yt-dlp on Windows vulnerable to `--exec` command injection when using `%q`",
  "details" : "### Impact\n[`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.\n\nHowever, 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`.\n\nSupport 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).\n\n```shell\n> yt-dlp https://youtu.be/Jo66yyCpHcQ --exec \"echo %(title)q\"\n[youtube] Extracting URL: https://youtu.be/Jo66yyCpHcQ\n[youtube] Jo66yyCpHcQ: Downloading webpage\n[youtube] Jo66yyCpHcQ: Downloading ios player API JSON\n[youtube] Jo66yyCpHcQ: Downloading android player API JSON\n[youtube] Jo66yyCpHcQ: Downloading m3u8 information\n[info] Jo66yyCpHcQ: Downloading 1 format(s): 135+251\n[download] Destination: "&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f135.mp4\n[download] 100% of    4.85KiB in 00:00:00 at 60.20KiB/s\n[download] Destination: "&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f251.webm\n[download] 100% of    4.80KiB in 00:00:00 at 31.58KiB/s\n[Merger] Merging formats into \""&echo(&echo(pwned&rem( [Jo66yyCpHcQ].mkv\"\nDeleting original file "&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f135.mp4 (pass -k to keep)\nDeleting original file "&echo(&echo(pwned&rem( [Jo66yyCpHcQ].f251.webm (pass -k to keep)\n[Exec] Executing command: echo \"\\\"&echo(&echo(pwned&rem(\"\n\"\\\"\n\npwned\n```\n\n### Patches\nyt-dlp version 2023.09.24 fixes this issue by properly escaping each special character.\n`\\n` will be replaced by `\\r`, as no way of escaping it has been found.\n\n### Workarounds\nIt 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.\n\nFor Windows users who are not able to upgrade:\n- Avoid using any output template expansion in `--exec` other than `{}` (filepath).\n- If expansion in `--exec` is needed, verify the fields you are using do not contain `\"`, `|` or `&`.\n- Instead of using `--exec`, write the info json and load the fields from it instead.\n\n### References\n- https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-42h4-v29r-42qg\n- https://nvd.nist.gov/vuln/detail/CVE-2023-40581\n- https://github.com/yt-dlp/yt-dlp/releases/tag/2023.09.24\n- https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/tag/2023.09.24.003044\n- https://github.com/yt-dlp/yt-dlp/commit/de015e930747165dbb8fcd360f8775fd973b7d6e",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "yt-dlp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2021.04.11"
      }, {
        "fixed" : "2023.09.24"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-42h4-v29r-42qg"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-40581"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/yt-dlp/yt-dlp/commit/de015e930747165dbb8fcd360f8775fd973b7d6e"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/yt-dlp/yt-dlp"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/tag/2023.09.24.003044"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/yt-dlp/yt-dlp/releases/tag/2021.04.11"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/yt-dlp/yt-dlp/releases/tag/2023.09.24"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-78" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-09-25T17:33:40Z",
    "nvd_published_at" : "2023-09-25T19:15:09Z"
  }
}