Offensive security researcherZagreb, Croatia
I break things on purpose, mostly firmware and the protocols underneath it. Nine years split between a national response unit and product security work, which means I have written both the advisory and the apology. I am considerably better at finding bugs than at estimating how long finding them will take.
Boots unmodified ARM firmware under a stubbed peripheral layer so fuzzers can reach code that normally needs the physical board. Open sourced in 2023 — about 1,900 stars and, more usefully, three vendors now run it in CI.
Eleven related findings in a widely deployed building controller, from an unauthenticated write primitive up to full firmware replacement. Coordinated disclosure ran fourteen months across five vendors and one national CERT.
Replaced a homegrown signature check with a properly rollback-protected chain, retrofitted onto hardware that shipped without a key store. The interesting constraint was that none of it could brick a device in the field.
A small terminal UI for diffing firmware images by structure rather than by bytes. Written almost entirely on trains. Roughly forty people use it and two of them have opinions.
Ivo told us our flagship feature was indefensible, then spent two weeks proving it rather than arguing about it. We shipped something narrower and much better.
He writes the clearest advisories I have read. Vendors who start out furious with him usually end up asking him to review the fix.
The building-controller chain end to end, including the fourteen months of email.
Halyard's design, and the peripherals we gave up on stubbing.
Thesis on side-channel leakage in constrained devices.