Many of those /are/ programmable. Here's the code we used to get code execution ...

xobs on Nov 10, 2018 | parent | context | favorite | on: How Many Computers Are in Your Computer?

Many of those /are/ programmable. Here's the code we used to get code execution on an SD card bought at the markets in Shenzhen (the project I did with bunnie, referenced above): https://github.com/xobs/ax2xx-code

The factory needs to get code on there somehow, and usually the method isn't documented. Oftentimes it's not locked down.

acqq on Nov 10, 2018 [–]

The blog entry "On Hacking MicroSD Cards" (2013):

https://www.bunniestudios.com/blog/?p=3554