COLDCARD 2021 Vulnerability Traced to Compiler Bypass Disabling Hardware RNG

Analysis reveals COLDCARD's 2021 flaw stemmed from disabling hardware RNG to fix compilation errors, forcing fallback to weaker software generator.

Woofun AI reports that technical analysis by Core-Lightning developer ddustin indicates the 2021 COLDCARD vulnerability originated from attempts to integrate Python code, MicroPython C code, and the STM32 hardware random number generator. Conflicts with existing MicroPython implementations likely triggered compiler errors, prompting developers to set MICROPY_HW_ENABLE_RNG to 0. This adjustment allowed successful firmware compilation but disabled the hardware random number generator for new wallets, causing a fallback to MicroPython's weaker Yasmarang software random number generator. The associated commit message contained only the word "runs."