# 414: Puff, the Magically Secure Dragon

- Show: [Embedded.fm](https://hardwarepodcasts.com/podcast/embedded-fm)
- Published: 2022-05-26
- Length: 58m
- Episode: 414
- Page: https://hardwarepodcasts.com/podcast/embedded-fm/2022-05-26-414-puff-the-magically-secure-dragon
- Listen: https://embedded.fm/episodes/414

## Summary

Laura Abbott, a firmware engineer at Oxide Computing, discusses two silicon bugs found in the NXP LPC55S69 microcontroller, including a buffer overflow in the ROM that allows cloning the device's PUF identity. She explains how she used Ghidra to reverse-engineer the undocumented ROM code and details the security implications for TrustZone and Secure Boot. The conversation also covers Oxide's approach to hiring, their use of Rust for firmware, and the challenges of working with proprietary silicon.

## Chapters

- [0:06](https://hardwarepodcasts.com/podcast/embedded-fm/2022-05-26-414-puff-the-magically-secure-dragon#t=6) Introduction and Oxide Computing Overview
- [4:40](https://hardwarepodcasts.com/podcast/embedded-fm/2022-05-26-414-puff-the-magically-secure-dragon#t=280) LPC55S69 Security Features and TrustZone
- [12:29](https://hardwarepodcasts.com/podcast/embedded-fm/2022-05-26-414-puff-the-magically-secure-dragon#t=749) Discovering the ROM Buffer Overflow Bug
- [19:33](https://hardwarepodcasts.com/podcast/embedded-fm/2022-05-26-414-puff-the-magically-secure-dragon#t=1173) Exploiting the Bug and Cloning Identity
- [38:05](https://hardwarepodcasts.com/podcast/embedded-fm/2022-05-26-414-puff-the-magically-secure-dragon#t=2285) Reverse Engineering with Ghidra
- [44:01](https://hardwarepodcasts.com/podcast/embedded-fm/2022-05-26-414-puff-the-magically-secure-dragon#t=2641) Oxide's Hiring Process and Rust in Firmware
- [51:00](https://hardwarepodcasts.com/podcast/embedded-fm/2022-05-26-414-puff-the-magically-secure-dragon#t=3060) Undocumented ROM Patching and Second Bug

## Topics

- [Debugging & failure analysis](https://hardwarepodcasts.com/topic/debugging-and-failure-analysis)
- [Microcontrollers & dev platforms](https://hardwarepodcasts.com/topic/microcontrollers-and-platforms)
- [Security & privacy](https://hardwarepodcasts.com/topic/security-and-privacy)
- [Embedded firmware](https://hardwarepodcasts.com/topic/embedded-firmware)
- [Hiring & workforce](https://hardwarepodcasts.com/topic/hiring-and-workforce)

## Most relevant to

early-stage companies

## Mentioned

- Oxide Computing (company)
- NXP (company)
- LPC55S69 (chip)
- Ghidra (tool)
- TrustZone (other)
- PyOCD (tool)
- OpenOCD (tool)
- Hardwear.io (other)
- NIST (company)
- ChipWhisperer (tool)

## Related episodes from other shows

- [Another LPC55 ROM Vulnerability](https://hardwarepodcasts.com/podcast/oxide-and-friends/2022-04-05-another-lpc55-rom-vulnerability) (Oxide and Friends)
- [055 - Stacks Of Bricked Chips](https://hardwarepodcasts.com/podcast/unnamed-reverse-engineering-podcast/2022-03-13-055-stacks-of-bricked-chips) (Unnamed Reverse Engineering Podcast)
- [Finding Hardware Flaws with Laura Abbott](https://hardwarepodcasts.com/podcast/the-amp-hour/2022-05-23-finding-hardware-flaws-with-laura-abbott) (The Amp Hour)
- [043 - Filling In  Zeros](https://hardwarepodcasts.com/podcast/unnamed-reverse-engineering-podcast/2020-12-21-043-filling-in-zeros) (Unnamed Reverse Engineering Podcast)
- [047 - The Sun, The Moon, The Stars](https://hardwarepodcasts.com/podcast/unnamed-reverse-engineering-podcast/2021-05-16-047-the-sun-the-moon-the-stars) (Unnamed Reverse Engineering Podcast)

## Citing this page

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