On September 10, 2019, researchers from VU Amsterdam published a whitepaper titled, “NetCAT, Practical Cache Attacks from the Network.” In scenarios where a malicious actor has a direct network connection to the target system, NetCAT may enable a Prime+Probe style exploit that targets processors supporting Intel® Data-Direct I/O Technology (Intel® DDIO) and Remote Direct Memory Access (RDMA) to disclose system information
This issue has a low CVSS base score of 2.6. In scenarios where Intel DDIO and RDMA are enabled, strong security controls on a secured network are required, as a malicious actor would need to have read/write RDMA access on a target machine using Intel DDIO to use this exploit. In the complex scenarios where Intel DDIO and RDMA are typically used, such as massively parallel computing clusters, malicious actors typically don't have direct access from untrusted networks.
Employing previously published best practices for side channel resistance in software applications and cryptographic implementations, including using constant-time style code, can mitigate the exploits described in this research.
More information can be found in Intel Security Advisory INTEL-SA-00290.