Any device that stores the actual password on the device itself is theoretically exploitable. The fact that a manufacturer would do this begs the question, why?
The only security product I would trust is an open-source one. To my knowledge, nobody has demonstrated an exploit against TrueCrypt or its more modern developments.
You might like to read this paper:
got HW crypto? - On the (in)security of a Self-Encrypting Drive series:
https://eprint.iacr.org/2015/1002.pdf