A redirect vulnerability in the fastify-static module version >= 4.2.4 and < 4.4.1 allows remote attackers to redirect Mozilla Firefox users to arbitrary websites via a double slash // followed by a domain: http://localhost:3000//a//youtube.com/%2e%2e%2f%2e%2e.

A DOS vulnerability is possible if the URL contains invalid characters curl --path-as-is "http://localhost:3000//^/.."The issue shows up on all the fastify-static applications that set redirect: true option. By default, it is false.