On STMicroelectronics STM32F7 devices, Proprietary Code Read Out Protection (PCROP) (a software IP protection method) can be defeated with a debug probe via the Instruction Tightly Coupled Memory (ITCM) bus.
stm32l4_firmware
CVE-2019-14236
On STMicroelectronics STM32L0, STM32L1, STM32L4, STM32F4, STM32F7, and STM32H7 devices, Proprietary Code Read Out Protection (PCROP) (a software IP protection method) can be defeated by observing CPU registers and the effect of code/instruction execution.