Rust at bottom corners of windshield

[DaddysTruck]

After pulling my dash I found rusty seams at the bottom corners of the windshield. It's like this on both sides. I've had issues with rain water running down to the floor pans from this area, and I think this may be the culprit. Is this where it comes through when the cowl rusts out, or what would cause this?

After removing the old seam sealer and wire cupping it.