Strapi has a rate limit bypass on users-permissions plugin via attacker-controlled email keying

Summary

Strapi is an open source headless content management system. In Strapi versions prior to 5.45.0, the rate-limit middleware in the users-permissions plugin derived its rate-limit key in part from `ctx.request.body.email`, including on routes whose body schema does not contain an `email` field (`/auth/local`, `/auth/reset-password`, `/auth/change-password`). An unauthenticated attacker could include an arbitrary `email` value in the request body to obtain a fresh rate-limit key per request, effectively bypassing per-IP throttling on those routes and enabling high-volume credential brute-force, password-reset code brute-force, and credential-stuffing attempts. The rate-limit key was constructed as `${userIdentifier}:${requestPath}:${ctx.request.ip}`, where `userIdentifier = ctx.request.body.email`. On routes that legitimately use email as their identifier (e.g. `/auth/forgot-password`, `/auth/local/register`), this scoping is correct. On routes that use a different identifier (`identifier` for login, `code` for password reset, `currentPassword` for password change), the email field was not part of the route contract, but the middleware still incorporated it into the key, allowing a caller to rotate the value and obtain a unique key on every request. The patch in version 5.45.0 maintains an allow-list of routes that legitimately key on the email field and excludes that key component on every other route the middleware is mounted on. OAuth callback paths (`/connect/*`) are treated identifier-less. On routes outside the allow-list, the middleware now falls back to a fixed identifier-less key, ensuring per-IP throttling remains effective even when the request body is attacker-controlled.