The flash read-out protection (RDP) level is not enforced during the device initialization phase of the SoloKeys Solo 4.0.0 & Somu and the Nitrokey FIDO2 token. This allows an adversary to downgrade the RDP level and access secrets such as private ECC keys from SRAM via the debug interface.
https://www.aisec.fraunhofer.de/en/FirmwareProtection.html
https://twitter.com/SoloKeysSec
https://github.com/solokeys/solo/commit/a9c02cd354f34b48195a342c7f524abdef5cbcec