A group of cybersecurity researchers have discovered a new security vulnerability affecting Intel processors, which they've craftily named "Plundervolt," a portmanteau of the words "plunder" and "undervolt." Chronicled under CVE-2019-11157, it was first reported to Intel in June 2019 under its security bug-bounty programme, so it could secretly develop a mitigation. With the 6-month NDA lapsing, the researchers released their findings to the public. Plundervolt is described by researchers as a way to compromise SGX (software guard extensions) protected memory by undervolting the processor when executing protected computations, to a level where SGX memory-encryption no longer protects data. The researchers have also published proof-of-concept code.

Plundervolt is different from "Rowhammer," in that it flips bits inside the processor, before they're written to the memory, so SGX doesn't protect them. Rowhammer doesn't work with SGX-protected memory. Plundervolt requires root privileges as software that let you tweak vCore require ring-0 access. You don't need direct physical access to the target machine, as tweaking software can also be remotely run. Intel put out security advisory SA-00298 and is working with motherboard vendors and OEMs to release BIOS updates that pack a new microcode with a mitigation against this vulnerability. The research paper can be read here.