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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.

Cloudflare Blog · 28d agoResearch

Risky Bulletin: Academics find source code overlaps between Geedge and China's Great Firewall

Academics linked Chinese vendor Geedge Networks' Tiangou Secure Gateway source code to one of the Great Firewall's three traffic filtering capabilities.

US researchers presenting at USENIX Security reconstructed Geedge Networks' Tiangou Secure Gateway firmware from over 100,000 leaked files, including Git repositories with commit history, and matched its filtering behavior to sections of China's Great Firewall. They found only 1 of 3 characterized DNS injectors matched Geedge code, noted the system relies on memory-unsafe C components and copied third-party code, and said its bugs could aid future circumvention tools. Geedge also exports censorship tools to Kazakhstan, Ethiopia, Pakistan, and Myanmar. The newsletter additionally rounds up multiple breaches.

Risky Business News · 26d agoResearch2

SCHERI: Provably Secure Speculation Under the Constant-Time Policy for CHERI (Extended Version)

Researchers formally prove existing CHERI speculation proposals leak secrets and present SCHERI, a processor design with end-to-end Spectre-resistant constant-time guarantees.

The paper builds a formal framework reasoning jointly about capability safety, speculative execution, and information-flow security on CHERI architectures. It demonstrates that existing secure-speculation proposals fail to preserve constant-time confidentiality guarantees and can transiently leak isolated secrets. The authors present SCHERI, a new processor design formally proven to provide end-to-end secure speculation for the constant-time policy, resilient to Spectre attacks.

arXiv cs.CR · 1d agoResearch