Summary:

Radically Open Security conducted a comprehensive code audit for the Tor Project between April 17, 2023, and August 13, 2023. The audit covered various components of the Tor ecosystem, including Tor Browser, exit relays, exposed services, and infrastructure components. The main goals were to assess software changes aimed at improving the Tor network's speed and reliability. Recommendations included reducing the attack surface of public-facing infrastructure, addressing outdated libraries, implementing modern web security standards, and following redirects in HTTP clients by default. The audit also emphasized fixing issues related to denial-of-service vulnerabilities, local attacks, insecure permissions, and insufficient input validation. The U.S. State Department Bureau of Democracy, Human Rights, and Labor sponsored the project, aiming to enhance the Tor network's performance and reliability in regions with internet repression.