PROJECT RAIN:L1TF

Summary from the TLDR InfoSec newsletter

L1TF Reloaded is a complex attack chain that uses half-Spectre gadgets to load data into L1 cache and L1 Terminal Fault to read cross-VM secrets via kernel data structures, breaking KASLR and extracting TLS keys. Google responded with Address Space Isolation (ASI), removing sensitive memory from kernel space during VM execution and mapping it during controlled transitions with buffer clearing. The attack highlights how speculative execution vulnerabilities can bypass privilege boundaries in virtualized environments, emphasizing the need for comprehensive architectural defenses beyond piecemeal mitigations.