CVE-2024-38519 yt-dlp and youtube-dl vulnerable to file system modification and RCE through improper file-extension sanitization

2024-07-0213:47:36

CWE-669

GitHub_M

github.com

yt-dlp

youtube-dl

file system modification

rce

improper file-extension sanitization

command-line

audio/video downloaders

version fix

path traversal

download folder

config

arbitrary code

extensions whitelist

exploitation surface limit

upgrade

output template

sensitive locations

config location.

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

SSVC

Exploitation

poc

Automatable

Technical Impact

total

JSON

yt-dlp and youtube-dl are command-line audio/video downloaders. Prior to the fixed versions, yt-dlp and youtube-dl do not limit the extensions of downloaded files, which could lead to arbitrary filenames being created in the download folder (and path traversal on Windows). Since yt-dlp and youtube-dl also read config from the working directory (and on Windows executables will be executed from the yt-dlp or youtube-dl directory), this could lead to arbitrary code being executed.

yt-dlp version 2024.07.01 fixes this issue by whitelisting the allowed extensions. youtube-dl fixes this issue in commit d42a222 on the master branch and in nightly builds tagged 2024-07-03 or later. This might mean some very uncommon extensions might not get downloaded, however it will also limit the possible exploitation surface. In addition to upgrading, have .%(ext)s at the end of the output template and make sure the user trusts the websites that they are downloading from. Also, make sure to never download to a directory within PATH or other sensitive locations like one’s user directory, system32, or other binaries locations. For users who are not able to upgrade, keep the default output template (-o "%(title)s [%(id)s].%(ext)s); make sure the extension of the media to download is a common video/audio/sub/… one; try to avoid the generic extractor; and/or use --ignore-config --config-location ... to not load config from common locations.

ADP Affected

[
  {
    "cpes": [
      "cpe:2.3:a:yt-dlp_project:yt-dlp:-:*:*:*:*:*:*:*"
    ],
    "vendor": "yt-dlp_project",
    "product": "yt-dlp",
    "versions": [
      {
        "status": "affected",
        "version": "0",
        "lessThan": "2024.07.01",
        "versionType": "custom"
      }
    ],
    "defaultStatus": "unknown"
  }
]