CVE-2023-48309 : Exploit Details and Defense Strategies

This article provides detailed information about CVE-2023-48309, a vulnerability affecting NextAuth.js.

Understanding CVE-2023-48309

NextAuth.js provides authentication for Next.js. The vulnerability affects

next-auth

applications prior to version 4.24.5 that rely on the default Middleware authorization.

What is CVE-2023-48309?

The vulnerability allows a bad actor to create an empty/mock user by manipulating a NextAuth.js-issued JWT from an interrupted OAuth sign-in flow. By overriding the session-token cookie value, an attacker can simulate a logged-in user without associated user information.

The Impact of CVE-2023-48309

While the vulnerability does not provide access to other users' data, bad actors can peek at logged-in user states, such as dashboard layouts.

next-auth

version 4.24.5 contains a patch for this vulnerability.

Technical Details of CVE-2023-48309

The following technical details outline the vulnerability:

Vulnerability Description

A bad actor can create a mock user with no user information by manipulating the JWT from an OAuth flow, exploiting Middleware authorization.

Affected Systems and Versions

next-auth

applications prior to version 4.24.5 are affected by this vulnerability.

Exploitation Mechanism

By intercepting the

next-auth.session-token

cookie value, attackers can simulate a logged-in user state.

Mitigation and Prevention

It is crucial to take immediate action to mitigate the risks posed by CVE-2023-48309. Here are the key steps to address this vulnerability:

Immediate Steps to Take

Developers are advised to upgrade to

next-auth

version 4.24.5 or higher to apply the necessary patch. Implementing a custom authorization callback for Middleware can provide additional protection against unauthorized access.

Long-Term Security Practices

In the long term, developers should adopt robust authentication mechanisms and regularly update their authentication frameworks to prevent similar vulnerabilities.

Patching and Updates

Regularly monitor security advisories from NextAuth.js and promptly apply patches and updates to maintain a secure authentication environment.