8.3 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
0.005 Low
EPSS
Percentile
77.1%
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.
Author | Note |
---|---|
rodrigo-zaiden | issue affects Windows only |
github.com/yt-dlp/yt-dlp-nightly-builds/releases/tag/2023.09.24.003044
github.com/yt-dlp/yt-dlp/commit/de015e930747165dbb8fcd360f8775fd973b7d6e
github.com/yt-dlp/yt-dlp/releases/tag/2021.04.11
github.com/yt-dlp/yt-dlp/releases/tag/2023.09.24
github.com/yt-dlp/yt-dlp/security/advisories/GHSA-42h4-v29r-42qg
launchpad.net/bugs/cve/CVE-2023-40581
nvd.nist.gov/vuln/detail/CVE-2023-40581
security-tracker.debian.org/tracker/CVE-2023-40581
www.cve.org/CVERecord?id=CVE-2023-40581