Frankly to suggest that an enterprise firewall would be susceptible to a simple path traversal attack is insane. Unless there's the most embarrassing news story of the decade im missing? That kind of input validation is baked into basically everything these days.

Maybe you'll land input validation using quadruple URL encoded '../' or something but even still I'd doubt that.

So the person who replied to you is 100% correct in what it's about, but it doesn't really explain the comic. Unless it was made in like a decade ago.