React Router DOM, a cornerstone library for declarative routing in React web applications, recently saw the release of version 7.0.1, a minor update following closely after version 7.0.0. Both versions maintain the core functionality expected by developers building single-page applications with complex navigation. The fundamental structure of the library remains consistent, with the dependencies, notably on react-router, mirroring corresponding version bumps between the two releases. devDependencies for testing and building, including tsup, react, react-dom, wireit, and typescript, also remain unchanged.
Key dependencies like react and react-dom are still specified as peer dependencies, requiring version 18 or greater, ensuring compatibility with modern React projects. The licensing, repository details, and author information remain identical, indicating no alterations in the overall project governance or origin.
The primary difference lies subtly within the packaged distribution size. Version 7.0.1 reflects a minor increment in the unpacked size, expanding to 5436 bytes from the previous version's 5414 bytes. This suggests the introduction of minimal adjustments, likely bug fixes, or minor performance improvements within the codebase. Additionally, version 7.0.1 was released on 2024-11-22 at 14:44:08.139Z, approximately seven hours after version 7.0.0 (2024-11-22T07:42:40.862Z). Developers should prioritize this update for potential stability enhancements.
All the vulnerabilities related to the version 7.0.1 of the package
React Router allows pre-render data spoofing on React-Router framework mode
After some research, it turns out that it's possible to modify pre-rendered data by adding a header to the request. This allows to completely spoof its contents and modify all the values of the data object passed to the HTML. Latest versions are impacted.
The vulnerable header is X-React-Router-Prerender-Data, a specific JSON object must be passed to it in order for the spoofing to be successful as we will see shortly. Here is the vulnerable code :
To use the header, React-router must be used in Framework mode, and for the attack to be possible the target page must use a loader.
Versions used for our PoC:
routes/ssr).data. In our case the page is called /ssr:We access it by adding the suffix .data and retrieve the data object, needed for the header:
X-React-Router-Prerender-Data header with the previously retrieved object as its value. You can change any value of your data object (do not touch the other values, the latter being necessary for the object to be processed correctly and not throw an error):As you can see, all values have been changed/overwritten by the values provided via the header.
The impact is significant, if a cache system is in place, it is possible to poison a response in which all of the data transmitted via a loader would be altered by an attacker allowing him to take control of the content of the page and modify it as he wishes via a cache-poisoning attack. This can lead to several types of attacks including potential stored XSS depending on the context in which the data is injected and/or how the data is used on the client-side.