- SGX is disabled by default, it has to be enabled for this exploit to be relevant
- POC requires privileged execution, at which point you can safely assume all is already lost
Anyone who has spent time around digital logic circuits will know that messing with voltages will cause errors. If the power lines are too low some transistors will not be able to switch their load. Or too high and you will cause parasitic losses or capacitance in unexpected places. This is actually a really nice attack to show off to people with an interest in computer/electrical engineering because it demonstrates how a basic design constraint can cascade in unexpected ways.
> SGX is disabled by default, it has to be enabled for this exploit to be relevant
This is an attack on SGX. If you are not using it, it is irrelevant regardless of whether it is enabled.
> POC requires privileged execution, at which point you can safely assume all is already lost
For SGX, this is different. The threat model behind SGX is that anything outside SGX (including OS, BIOS, motherboard, etc.) is untrusted. The whole motivation behind SGX is to create a trusted environment in an untrusted host.
First, this is explicitly a vulnerability compromising SGX itself, so saying SGX has to be enabled is tautological. It's not a vulnerability attacking Intel processors generally, and it's not being billed that way either.
Second, securing memory against untrusted privileged execution is a defining characteristic of SGX, so it's likewise unsurprising that it would be required. That is quite literally the intended purpose of SGX.
The design thesis of SGX is to prevent "all hope is lost" from being true in the context of privileged execution.
- SGX is disabled by default, it has to be enabled for this exploit to be relevant
- POC requires privileged execution, at which point you can safely assume all is already lost
Anyone who has spent time around digital logic circuits will know that messing with voltages will cause errors. If the power lines are too low some transistors will not be able to switch their load. Or too high and you will cause parasitic losses or capacitance in unexpected places. This is actually a really nice attack to show off to people with an interest in computer/electrical engineering because it demonstrates how a basic design constraint can cascade in unexpected ways.