React Router, a popular declarative routing library for React applications, released version 7.0.1 shortly after version 7.0.0. Both versions share the same core dependencies, including cookie, turbo-stream, @types/cookie, and set-cookie-parser, ensuring consistent handling of cookies and turbo stream functionality. Similarly, the development dependencies for building and testing, such as tsup, react, rimraf, wireit, react-dom, typescript, and @types/set-cookie-parser, remain identical, indicating a stable development environment. The peer dependencies also haven't changed, requiring React and React DOM versions 18 or higher.
The key difference lies in the dist object, specifically the unpackedSize. Version 7.0.1 has a slightly larger unpacked size (2268855 bytes) compared to version 7.0.0 (2267994 bytes). This suggests minor code adjustments, potentially bug fixes, performance enhancements, or documentation updates. Developers upgrading from 7.0.0 to 7.0.1 should expect a minimal change in bundle size.
The release dates also reveal that version 7.0.1 was published just hours after version 7.0.0. This rapid release cycle often indicates a quick patch to address a critical issue discovered immediately after the initial 7.0.0 release. While the changelog might offer further clarification, developers focused on stability should carefully evaluate the changes. It is a minor update but it can contain important bug fixes, therefore upgrading from version 7 is recommended. Both versions expose the same API and features.
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.