This year started with some bad news for the Intel CPU owners when news surfaced about the Spectre and Meltdown vulnerabilities that affect all the Intel processors dating as far back as 1995. And now researchers have found that Intel processors are vulnerable to something called Zombieland or MDS (Michroarchitectural Data Sampling) attacks. This new vulnerability affects all the processors manufactured since 2011.
What are zombieland or MDS attacks?
Intel processors use something called speculative execution to make processing of data inside the CPU cache faster. The processor uses microachitectural data structures such as load, store and line buffers inside these caches. By exploiting the normal speculative execution operations, a process can get the data being processed inside the CPU cache even though this process should not have any access to it. This way any process can read the data being processed by any other process without requiring any permissions.
Depending on the microarchitectural data structure type targetted, researchers have found four such possible MDS attacks. One of these is more severe and targets the line fill buffers inside the CPU and is being labeled zombieland.
How to check if your Intel CPU is vulnerable to MDS attacks?
Security researchers have developed MDS Tool that is available for Windows and Linux. This tool shows all the information related to the MDS attacks. It shows vulnerability status for speculative execution such as direct branch speculation, indirect branch speculation, speculative store bypass. It also displays meltdown and microarchitectural data sampling vulnerability status.
Fortunately, my notebook’s CPU seems to be unaffected by the line fill buffer MDS attacks (zombieland) as well as other three types of MDS attacks (store buffers, load ports, and uncached memory).
How to protect yourself from MDS attacks?
Intel is going to provide micro-code updates for all the affected processors and after the updates your CPU will become unaffected by any of these MDS attacks. Intel also suggests disabling Intel Hyper-Threading Technology which can be done from the UEFI or BIOS settings.
For more information about MDS attacks on Intel processors and for downloading MDS Tool, you can visit https://mdsattacks.com/.