For Meltdown there was a simple solution with the "KAISER" patch available, developed by the TU Graz team, which however affected the speed of the computer to some extend. For ZombieLoad attacks a solution could be more difficult, as Gruss explains: "Each CPU has several cores and each core is split again. This allows several programs to run simultaneously. According to our analysis, one of these two areas must be deleted." This would mean performance losses of 50 percent. Or in a cloud that is also threatened by the attack method, 50 percent fewer potential users on the same hardware. All processors developed by Intel between 2012 and early 2018 will be affected.
Store-to-leak forwarding also exploits the optimized working methods of computer processors and reads preloaded data. "The computer assumes that I want to reuse the data that I have just written into the processor. So it keeps them in the buffer in order to be able to access them more quickly," explains Gruss. This way of working can be used again to explore the architecture of the computer processor and find the exact location where the operating system is running. "If I know exactly where the operating system is running by the processor, I can launch targeted attacks on operating system vulnerabilities."
The researchers reported the discoveries to the manufacturer Intel, which is now working on a solution. "All computer users should urgently install all new updates so that their computer systems are safe again," Gruss recommends.
Further information on ZombieLoad: https://zombieload.com/zombieload.pdf
Further information on Store-to-Leak Forwarding: https://cpu.fail/store-to-leak.pdf