GHSA-jcxm-m3jx-f287

Summary

simple-git enables running native Git commands from JavaScript. Some commands accept options that allow executing another command; because this is very dangerous, execution is denied unless the user explicitly allows it. This vulnerability allows a malicious actor who can control the options to execute other commands even in a “safe” state where the user has not explicitly allowed them. The vulnerability was introduced by an incorrect patch for CVE-2022-25860. It is likely to affect all versions prior to and including 3.28.0.

Detail

This vulnerability was introduced by an incorrect patch for CVE-2022-25860.

It was reproduced in the following environment:

WSL Docker
node: v22.19.0
git: git version 2.39.5
simple-git: 3.28.0

The issue was not reproduced on Windows 11.

The -u option, like --upload-pack, allows a command to be executed.

Currently, the -u and --upload-pack options are blocked in the file simple-git/src/lib/plugins/block-unsafe-operations-plugin.ts.

function preventUploadPack(arg: string, method: string) {
   if (/^\s*--(upload|receive)-pack/.test(arg)) {
      throw new GitPluginError(
         undefined,
         'unsafe',
         `Use of --upload-pack or --receive-pack is not permitted without enabling allowUnsafePack`
      );
   }

   if (method === 'clone' && /^\s*-u\b/.test(arg)) {
      throw new GitPluginError(
         undefined,
         'unsafe',
         `Use of clone with option -u is not permitted without enabling allowUnsafePack`
      );
   }

   if (method === 'push' && /^\s*--exec\b/.test(arg)) {
      throw new GitPluginError(
         undefined,
         'unsafe',
         `Use of push with option --exec is not permitted without enabling allowUnsafePack`
      );
   }
}

However, the problem is that command option parsing is quite flexible.

By brute forcing, I found various options that bypass the -u check.

[
  '--u', '--u',
  '-4u', '-6u',
  '-lu', '-nu',
  '-qu',...