[geogriffin]

The Plundervolt [1] paper is one study in what exactly goes haywire when a processor is undervolted. They found that the computation errors induced are quite consistent and reproducible. MUL and DIV are vulnerable, and AES-NI happened to be particularly badly broken in the face of undervolting.

[1] https://plundervolt.com/

[ngneer]

Indeed. CLKSCREW is the progenitor of that work. Note that in the context of security, it only matters if undervolting can cross security boundaries. This was possible on Intel systems at the time of Plundervolt but has since been fixed.