Versions of ascii-art before 1.4.4 are vulnerable to command injection. This is exploitable when user input is passed into the argument of the ascii-art preview command.

Example Proof of concept:
ascii-art preview 'doom"; touch /tmp/malicious; echo "'

Given that the input is passed on the command line and none of the api methods are vulnerable to this, the likely exploitation vector is when the ascii-art comment is being called programmatically using something like execFile.

Recommendation

Update to version 1.4.4 or later.

References

• https://hackerone.com/reports/390631
• https://github.com/nodejs/security-wg/blob/master/vuln/npm/471.json
• https://www.npmjs.com/advisories/727