Dependency Confusion

A dependency confusion attack or supply chain substitution attack occurs when a software installer script is tricked into pulling a malicious code file from a public repository instead of the intended file of the same name from an internal repository.

Summary

• Tools
• Exploit
• References

Exploit

Look for npm, pip, gem packages, the methodology is the same : you register a public package with the same name of private one used by the company and then you wait for it to be used.

NPM example

• List all the packages (ie: package.json, composer.json, ...)
• Find the package missing from https://www.npmjs.com/
• Register and create a public package with the same name
  • Package example : https://github.com/0xsapra/dependency-confusion-expoit

References

• Exploiting Dependency Confusion - 2 Jul 2021 - 0xsapra
• Dependency Confusion: How I Hacked Into Apple, Microsoft and Dozens of Other Companies - Alex Birsan - 9 Feb 2021
• Ways to Mitigate Risk When Using Private Package Feeds - Microsoft - 29/03/2021