Semiconductor giant Intel seems to be having a rough year when it comes to its core strength – processors. The company has disclosed a new vulnerability that exploits the lazy state restore technique, which could allow an attacker to read data through a speculative execution side channel.
Dubbed as “Lazy FP State Restore” the vulnerability was given a moderate rating by Intel, but as it resides in the CPU, it affects all Intel Core-based microprocessors, irrespective of the type of OS being used.
The security boundaries that may be affected by this vulnerability include virtual machine, kernel, and process.
Is it another Meltdown?
According to experts, the latest vulnerability is not a hardware issue like Spectre and Meltdown and can be fixed with a patch. Red Hat is reportedly already working on a patch, and Microsoft has also released a security advisory on the issue.
It’s not as severe as the other two chip-level vulnerabilities – Spectre and Meltdown, discovered in January 2018, which also had an impact on ARM and AMD processors.
Deconstructing Lazy FP State Restore
The latest vulnerability exploits the way modern CPUs function. Today, CPUs contain several registers that represent a running application. To optimize performance while switching from one application to another, the Lazy FP State Restore technique delays the restoring of state until an instruction is actually executed.
According to Intel, the Lazy restored states are potentially vulnerable to exploits where one process may infer register values of other processes through a speculative execution side channel that infers their value.
This implies a malicious actor could read the floating point registers of other applications, including the encrypted ones.
The vulnerability affects recent Intel CPUs - from Sandy Bridge to other processors. However, it doesn’t seem to have an impact on AMD processors.