Speculative execution enhanced microprocessor performance, but also made them more susceptible to side-channel attacks. The final fix won’t be via software updates.
Foreshadow/L1TF refer to a group of vulnerabilities that can be exploited in modern Intel chips using speculative execution attacks to bypass security protections and harvest sensitive information.
NetSpectre is not an immediate threat: no known malware exists in the wild. The research is important because it deepens our understanding of microprocessor architecture and ways speculative execution can be abused.
The Spectre and Meltdown hardware bugs have pushed vendors such as Google to rethink how they deploy defenses.