CVE-2024-46982 - Next.js SSR Cache Poisoning in Non-Dynamic Routes: Vulnerability and Mitigation

In this post, we will discuss a vulnerability found in the Next.js framework CVE-2024-46982. Next.js is a popular React framework known for its simplicity and performance, often used for building full-stack web applications. By understanding the exploit details and applying the recommended fixes, developers can prevent their application from falling prey to this vulnerability.

This vulnerability affects Next.js server-side rendering (SSR) and involves poisoning the cache of a non-dynamic route in the pages router. The vulnerability may lead to incorrect caching of routes that are not meant to be cached.

You are using the pages router

3. Your application has non-dynamic server-side rendered routes, e.g., pages/dashboard.tsx, not pages/blog/[slug].tsx.

Exploit Details

An attacker can exploit this vulnerability by sending a crafted HTTP request, which causes Next.js to cache a route that should not be cached and send a Cache-Control: s-maxage=1, stale-while-revalidate header. Some upstream CDNs may cache this as well, allowing an attacker to potentially control the content served to other users.

Here is an example of a crafted HTTP request that could trigger the vulnerability

GET /dashboard HTTP/1.1
Host: vulnerable-app.com
User-Agent: AnyBrowser
Connection: close
X-Forwarded-Host: evil-attacker.com

When the Next.js application receives this request, it treats it as a cacheable request for the /dashboard route, even though it's not intended to be cached.

Mitigation

This vulnerability has been resolved in Next.js versions 13.5.7, 14.2.10, and later. We highly recommend upgrading your Next.js application to the latest version, regardless of whether you can reproduce the issue or not. Upgrading will not only protect you from this vulnerability but also bring performance improvements and new features.

Open your project's package.json file in a text editor.

2. Locate the "next" dependency in the "dependencies" section and update its version number to "latest" or the desired version (e.g., ^13.5.7 or ^14.2.10).

Conclusion

Security vulnerabilities, like the one discussed in this post, serve as an important reminder to keep your software up-to-date and be diligent about monitoring and addressing security issues. By staying informed and taking the necessary precautions, you can help protect your web applications from potential attacks and ensure the safety of your users.

Timeline

Published on: 09/17/2024 22:15:02 UTC
Last modified on: 09/20/2024 12:30:51 UTC