  This paper presents results from the MSR 2021 Hackathon. Our team
investigates files/projects that contain known security vulnerabilities and how
widespread they are throughout repositories in open source software. These
security vulnerabilities can potentially be propagated through code reuse even
when the vulnerability is fixed in different versions of the code. We utilize
the World of Code infrastructure to discover file-level duplication of code
from a nearly complete collection of open source software. This paper describes
a method and set of tools to find all open source projects that use known
vulnerable files and any previous revisions of those files.
