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stonegrayyesterday at 8:53 PM2 repliesview on HN

> “and is writable with CAP_SYS_ADMIN”

Am I reading this wrong or is this just a way of executing an arbitrary binary with uid=0 if you have both CAP_NET_ADMIN and CAP_SYS_ADMIN?

If you can write modprobe_path, is it really news that you can find a way to execute code?


Replies

PlasmaPoweryesterday at 9:48 PM

No, you can grant yourself this inside an unprivileged user namespace. `unshare -Ur capsh --print` lists the capabilities inside a user namespace and demonstrates that it has both CAP_SYS_ADMIN and CAP_NET_ADMIN.

Almost all distros allow unprivileged user namespaces, and in my opinion this is the right decision, because they're important for browser sandboxing which I think is more important than LPEs.

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pizzalifeyesterday at 9:10 PM

Right. `CAP_SYS_ADMIN` is for all intents and purposes equivalent to root.