A revisit of remote Spectre attacks on Cloudflare Workers
In 2021, we assessed remote Spectre attacks against Cloudflare Workers. Based on the results, we shipped a production defense called Dynamic Process Isolation (DyPrIs), which identifies maliciously looking scripts and isolates them into separate processes. Since then, newer techniques in the area of stabilizing Spectre attacks have been discovered. To understand if these techniques posed a threat to our Workers production environment, we decided to internally reassess the remote Spectre attack.