A new side-channel vulnerability has been found called PortSmash that uses a timing attack that to steal info from other processes running in the same CPU core with SMT/hyper-threading enabled.
Utilizing this attack, researchers were able to steal the private decryption key from an OpenSSL thread running in the same core as their exploit.
For those that dont know, SMT/Hyper-threading is when one physical CPU core is split into two virtual logical cores that can be used two run two separate process threads at once.
This method can increase performance as the two threads will utilize idle CPU resources more efficiently to execute instructions faster.
A side channel timing attack is when an attacker analyzes how fast a thread executes particular instructions and utilizes that info to work backwards to discover what data was used as input.
The PortSmash vulnerability was discovered by researchers Billy Bob Brumley, Sohaib ul Hassan, Cesar Pereida Garcia, and Nicola Tuveri from the Tampere University of Technology in Finlan