Two vulnerabilities were found in 2018 in modern computer processors: Meltdown, and Spectre. These vulnerabilities can allow an attacker access to sensitive information such as passwords and personal data stored in a computer’s memory.
Meltdown is an attack on Intel processors that allows an attacker bypass hardware-based protection mechanisms to prevent sensitive information from being accessed. This vulnerability is specific to how Intel processors handle memory acces. A computer stores data in its memory when it processes instructions. This data is stored in the processor’s memory, which allows it to retrieve it as necessary to execute the instructions.
The processor can only access the data it needs. It cannot access any other data stored in the memory. The Meltdown vulnerability lets an attacker access these other data through a flaw with the processor’s handling of memory access. The processor uses a technique known as “speculative execution” to predict what data it will require and then access it before it actually needs it. An attacker could potentially gain access to data they shouldn’t have by manipulating this process.
Spectre is a vulnerability that can affect processors from several manufacturers including Intel, AMD and ARM. This vulnerability is more general and is caused by the way processors use branch prediction to speed up execution of instructions. Branch prediction allows the processor to predict which instructions it will need next by using the instructions it has already executed. This allows the processor, which can significantly increase processor speed, to begin executing the next set before it finishes the current set.
Spectre exploits this to allow an attacker to trick the processor into executing commands it shouldn’t. You can manipulate the data the processor is currently working on to cause it execute instructions it wouldn’t normally. An attacker could gain access to sensitive information stored in the processor’s RAM by doing this.
You can take several steps to protect yourself from both Meltdown or Spectre. These are:
- Patching: This is the best way to protect yourself against these vulnerabilities. These patches address the underlying vulnerabilities that enable Meltdown or Spectre to be exploited.
- Kernel protection: Linux and other operating systems have implemented kernel protection measures to help mitigate the risks of Meltdown or Spectre. Kernel Page Table Isolation, (KPTI) which isolates the kernel’s memories from the rest of system memory, and Retpoline which helps to prevent speculative execution attack, are some examples.
- Virtualization: Virtualization is a way to isolate parts of the system from one another, which can be useful in protecting against Meltdown or Spectre. Virtualization is a good option to avoid vulnerabilities that rely on the ability to access data stored in the processor’s RAM.
- Hardware-based protection: Some processors offer hardware-based protection that can reduce the risk of Meltdown or Spectre. Intel, for example, has implemented hardware-based protection in its latest processors. This includes the “Hardware Enhanced Mitigation” feature that is intended to protect against speculative execution attacks.
It is essential to keep up to date with security patches and other measures to guard against Meltdown or Spectre. These vulnerabilities pose a serious threat to computer security.