Cloudflare Workers Spectre Attack Leaks JWT From Co-Located Worker at 12 Bits/Second

Cybersecurity researchers have revealed a remote Spectre attack on Cloudflare Workers, demonstrating the ability to leak a JSON Web Token from a co-located Worker. The attack was carried out in a production environment and achieved a leakage rate of up to 12 bits per second. This rate is significantly higher than a similar attack shown in 2021, with the new attack being 360 times faster. The researchers conducted an end-to-end experiment using two Workers, one acting as the attacker and the other as the victim, both of which were under their control. The experiment showcased the potential vulnerability of Cloudflare Workers to Spectre attacks.