Last year, we discovered an undocumented hardware block in the LPC55S69 (our chosen part for our product’s Root of Trust implementation) that could be used to violate security boundaries. This issue highlighted the importance of transparency as an Oxide value which is why we are bringing another recently discovered vulnerability to light today. While continuing to develop our product, we discovered a buffer overflow in the ROM of the LPC55S69. This issue exists in the In-System Programming (ISP) code for the signed update mechanism which lives in ROM. This vulnerability allows an attacker to gain non-persistent code execution with a carefully crafted update regardless of whether the update is signed.

source: HN