It seems that this is not Intel’s best year. Spectre and Meltdown began to emerge at the beginning of this year. The big giants were badly affected, not just Intel, but AMD as well. During the course of the year, even further vulnerabilities were discovered in connection with these chips. Now, as we thought the vulnerabilities were over, there comes PortSmash, which affects HyperThreading on Intel processors. AMD may be affected, but is not yet known for sure.
PortSmash exploits a vulnerability in Intel’s HyperThreading technology. This is a proprietary technology that splits a physical core into two independent processing threads. This reduces the time required to perform parallel tasks.
PortSmash affects the latest Intel processors on the market
If you’ve been thinking about buying a state-of-the-art processor to escape Spectre and Meltdown, you will not escape from PortSmash. This vulnerability has been tested with an attack that allows encryption keys to be stolen. The researchers used a TLS server with OpenSSL. It was found to work with Skylake (6th generation) and Kaby Lake (7th generation) processors under Ubuntu.
The vulnerability, called CVE-2018-5407, is present on both computers and servers. Although it is easier to take advantage of the exploit in seconds. Researchers have come to design a system that allows you to customize the attack depending on the device you want to attack.
At the moment they have only tested with Skylake and Kaby Lake based chips, although researchers claim that later architectures are also affected. A minor change to the exploit would also be vulnerable. Even SMT, the HyperThreading counterpart to AMD has been compromised.
The most viable scenario for this type of attack is when the attacker is granted access to a server environment. If there are multiple people using virtual environments, you can view the information running in other processes running in parallel on the same server. Spectre could be used using a JavaScript that we downloaded from a website. Although they couldn’t check with PortSmash.
The only current solution is to disable HyperThreading
This June a vulnerability was discovered, although it was less significant in HyperThreading, called TLBleed. This vulnerability also made it possible to know encryption codes and researchers were able to guess a 256-bit encrypted key. This forced the OpenBSD developers to disable HyperThreading, and they recommended doing the same with SMT on computers with AMD processors.
Currently, the only way to protect against this attack is to disable HyperThreading and SMT in our motherboard’s UEFI/BIOS, which leads to a loss of performance. In the case of OpenSSL, an upgrade to version 1.1.1 or higher is recommended to protect against this attack. If you purchase a 9th generation i3, i5 or i7 processor, you are protected from this failure because these new chips do not have HyperThreading.