A revisit of remote Spectre attacks on Cloudflare Workers
Cloudflare details its 2024-2025 reassessment of remote Spectre attacks on Workers, covering new attack primitives and hardened defenses.
Cloudflare reassessed the feasibility of remote Spectre attacks against its Workers serverless infrastructure across 2024 and 2025. The write-up describes new attack primitives including Spectre gadgets, remote timers, and techniques for achieving co-location with victim workloads. It also explains new defenses that further harden Cloudflare Workers against speculative-execution side channels.