4 ms·
Most of the attacks I see on Nordic devices are power based attacks, where cutting the power for a brief instant causes protection instructions not to run. Thi
by nick0garvey 3y ago
Most of the attacks I see on Nordic devices are power based attacks, where cutting the power for a brief instant causes protection instructions not to run.
This one is entirely different, and attacks the initialization code directly. This code has no restrictions on its ability to access memory, allowing a full dump.
Great method.
- rx_tx 3y agoUnless I misunderstood the article [1], it describes this very same HW-based method of power glitching the chip at a crucial time using an external STM32F0 controlling the Vcore going to the nRF. Basically preventing it from checking if it's correctly locked or not at boot. After managing to connect through glitching, they dump the FW, then turn off APPROTECT, reflash, and have open debug access. >Our attack setup thus consists out of 1) a transistor connected to the CPU core supply voltage and ground, 2) a dev board to control the glitch timing, and 3) a debug probe to try to access the debug interface. [1]: https://www.emproof.com/attacking-microcontroller-readout-protections-with-fault-attacks/ https://www.emproof.com/attacking-microcontroller-readout-pr...
- rft 3y agoJust for clarification, the TFA is about the nRF51 which can be attacked via a debugger only. No glitching or other hardware was needed. Your link is a different attack on the newer nRF52 series which no longer has the same weakness in its debug handling.
- rx_tx 3y agoThanks. I guess the top link pointing to the team's homepage and not the specific article is definitely confusing.