You can always push and execute a "custom" installer like that through a Custom Action.
In this instance, though, I might recommend pushing the latest Software Distribution for Firefox instead of the patch instead. Software distributions are full installers, so that method would provide a fresh, full install of Firefox on anything you pushed it to and also be able to report on it (which the Custom Action can't do). Following the steps in this document, you'll look for QFF5701N (the full installer distributions like this have an N at the end of the QNumber), then deploy on those results.
I hope that helps. If you run into any issues with this, go ahead and open a support case. We're happy to help you make sure this works as you intend.