It's not quite ideal hardware due to only having a single NIC, but you can slap a USB NIC on it and make it work, if that's what's handy.

Old thin clients are typically in the same hardware class, and probably cheaper by the time you add the exploding MSRP of a Pi, and a PSU, and a case and heatsink, and maybe some storage that doesn't suck ass. But if you already own the Pi, yeah, go for it.