Deno is Vulnerable to Command Injection on Windows During Batch File Execution

### Summary Deno versions up to 2.5.1 are vulnerable to Command Line Injection attacks on Windows when batch files are executed. ### Details In Windows, ``CreateProcess()`` always implicitly spawns ``cmd.exe`` if a batch file (.bat, .cmd, etc.) is being executed even if the application does not specify it via the command line. This makes Deno vulnerable to a command injection attack on Windows as demonstrated by the two proves-of-concept below. ### PoC Using `node:child_process` (with the `env` and `run` permissions): ```JS const { spawn } = require('node:child_process'); const child = spawn('./test.bat', ['&calc.exe']); ``` Using `Deno.Command.spawn()` (with the `run` permission): ```JS const command = new Deno.Command('./test.bat', { args: ['&calc.exe'], }); const child = command.spawn(); ``` ### Impact Both of these scripts result in opening calc.exe on Windows, thus allowing a Command Line Injection attack when user-provided arguments are passed if the script being executed by the child process is a batch script.

Source published

8 Oct 2025 18:16:24 UTC

Source modified

8 Oct 2025 18:42:29 UTC

Observed here

24 Oct 2026 13:19:54 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Publisher rating · HIGH