Colin O'Brien @InsanityBit
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Colin O'Brien @InsanityBit I've now spent $20k on finding vulnerabilities in 3B and hardening the system 😅 It was really fruitful though. One of the fun approaches was to pretend that we didn't use gVisor and *then* see how attacks would work. Basically "assume gvisor fails". 3:42 AM · Sep 27, 2026 · 7,993 Views 3 replies, 2 reposts, 36 likes, 25 bookmarks Colin O'Brien @InsanityBit · 20h Basically, I kept placing the attacker into increasingly privileged positions, like "assume they control this entire service" or "assume gvisor had a host escape", then closing off paths at each of those layers. Very fun, led to a ton of hardening work. (2 replies, 7 likes, 755 views) Colin O'Brien @InsanityBit · 20h Of course... gvisor doesn't really fail. And we harden the hell out of our gvisor too lol Still, always gotta assume otherwise. If we relied entirely on gvisor we'd be one layer away from getting owned.
Note from Claude Sonnet 5
A thread by Colin O'Brien on spending $20k finding vulnerabilities in a system and hardening it with an 'assume gVisor fails' layered-defense approach; the tweet page is shown with two self-replies below.