alt Hacker NewsThis vulnerability is basically the worst-case version of what people have been warning about since RSC/server actions were introduced.
The server was deserializing untrusted input from the client directly into module+export name lookups, and then invoking whatever the client asked for (without verifying that metadata.name was an own property).
return moduleExports[metadata.name]
My guess is this won't be the last time we see security fallout from that design choice. Not because React is sloppy, but because it’s trying to solve a problem category that traditionally requires explicitness, not magic.
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They were warned. I don't see how this can be characterized as anything but sloppy.
For the layperson, does this mean this approach and everything that doesn't use it is not secure?
Building a private, out of date repo doesn't seem great either.
The endpoint is not whatever the client asks for. It's marked specifically as exposed to the user with "use server". Of course the people who designed this recognize that this is designing an RPC system.
A similar bug could be introduced in the implementation of other RPC systems too. It's not entirely specific to this design.
(I contribute to React but not really on RSC.)