CVE-2023-48309 Information

Description

NextAuth.js provides authentication for Next.js. next-auth applications prior to version 4.24.5 that rely on the default Middleware authorization are affected by a vulnerability. A bad actor could create an empty/mock user by getting hold of a NextAuth.js-issued JWT from an interrupted OAuth sign-in flow (state PKCE or nonce). Manually overriding the next-auth.session-token cookie value with this non-related JWT would let the user simulate a logged in user albeit having no user information associated with it. (The only property on this user is an opaque randomly generated string). This vulnerability does not give access to other users’ data neither to resources that require proper authorization via scopes or other means. The created mock user has no information associated with it (ie. no name email access_token etc.) This vulnerability can be exploited by bad actors to peek at logged in user states (e.g. dashboard layout). next-auth v4.24.5 contains a patch for the vulnerability. As a workaround using a custom authorization callback for Middleware developers can manually do a basic authentication.

Reference

https://github.com/nextauthjs/next-auth/security/advisories/GHSA-v64w-49xw-qq89 https://github.com/nextauthjs/next-auth/commit/d237059b6d0cb868c041ba18b698e0cee20a2f10 https://authjs.dev/guides/basics/role-based-access-control https://next-auth.js.org/configuration/nextjs#advanced-usage https://next-auth.js.org/configuration/nextjs#middlewar