MIT boffins' TONTOU attack slips through Spectre defenses on Intel and AMD CPUs
Summary
Researchers at MIT have discovered a new speculative execution attack called TONTOU that bypasses existing defenses against Spectre vulnerabilities on Intel and AMD CPUs. The attack exploits timer interrupts to reopen a window for branch predictor poisoning.
IFF Assessment
This discovery represents a new class of vulnerability that could allow attackers to extract sensitive information from modern CPUs.
Severity
The attack has a high impact on confidentiality as it can leak sensitive data, and it has a relatively low attack complexity due to the nature of speculative execution.
Defender Context
This research highlights ongoing challenges in securing modern CPU architectures against side-channel and speculative execution attacks. Defenders need to stay aware of emerging vulnerabilities like TONTOU and be prepared for potential mitigation strategies that may involve microcode updates or architectural changes.