GoKawiilToday Reuters and the Wall Street Journal both reported about rogue AI agents at OpenAI attacking RubyGems.org. https://www.rubyhack.ai/ has an amazing writeup, and you should read it. I just wanted to make a quick post about it because it’s wild.
TL;DR: It seems like OpenAI Bots knew about this caching vulnerability, tried to take advantage of it, and at the same time ran some weird web scraping code on RubyDoc.info.
Back in May, socket.dev reported about a “GemStuffer Campaign” where someone (I guess OpenAI) was uploading tons of junk gems to RubyGems.org. For some reason, the gems would scrape UK government websites, then repackage the data as gems, and attempt to upload them to RubyGems.
I honestly didn’t think much about this (or even look into it) until Sydney Von Arx and Spencer Kitts (both co-authors on https://www.rubyhack.ai) contacted me asking about RubyGems. I thought the claims they were making were completely outlandish until I actually read the code in these “GemStuffer” gems.
After reading the code in these gems, a couple things stood out to me.
YARD Documentation
First, the gems leverage YARD documentation to execute arbitrary code on host machines. In most of the examples you’ll see a .yardopts file that looks like this:
--load ./script.rb README.md lib/**/*.rb
Here’s a link to an example.
If you have YARD installed, and you install this gem, then YARD will load and run whatever is in ./script.rb from inside the gem. I think it’s pretty common knowledge that C extensions will execute extconf.rb (so you basically have an RCE vector), but I was surprised to find out that a documentation tool would do that too.
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