🟠 High | Source: The Hacker News
Researchers at MIT CSAIL have discovered a new CPU side-channel attack called INTERRUPT INJECTION that can bypass all default Spectre v2 mitigations on Intel and AMD processors running Linux. An unprivileged user-space process can time a hardware interrupt to re-poison the branch predictor immediately after the kernel has sanitised it, rendering existing defences ineffective. This matters because it affects any shared Linux environment — including cloud virtual machines — where untrusted workloads run alongside sensitive kernel operations.
Security Architect’s Take: Until kernel patches are available and deployed by cloud providers, consider enforcing stronger workload isolation by running sensitive workloads on dedicated bare-metal instances or single-tenant VMs, and engage your cloud provider on their patch timeline. For multi-tenant environments, evaluate whether disabling simultaneous multithreading (SMT) is operationally feasible as an interim risk reduction measure.
Original advisory: New Interrupt Injection Attack Can Bypass Spectre v2 Defenses on Intel and AMD CPUs