[BUG] Old Bootstrap's versions not appear as vulnerables

[MatiSanchez]

Describe the bug
In Bower, 2 weeks ago, old versions of bootstrap appear as vulnerables:

But the last few days, no vulnerability was found:

And then I found this: : https://ossindex.sonatype.org/updates-notice (The vulnerability URL in the second image returns 404)

Maybe you need to update vulnerability IDs?

Thanks!

Expected behavior
Old versions of Bootstrap are vulnerables.

AuditJS Version : 4.0.37

cc @bhamail / @DarthHater / @allenhsieh / @Slim-Shary