Title. Just had this baseless yet possible idea on my head and I’d like to know how wrong it is? Since afaik, “nobody” has absolutely zero permissions… other than the ones given by the user. Pretty sure I’m missing something vital or important, but… I’m completely fine being called dumb every now and then.
Thanks in advance.
A process owned by any user will be able to exploit a userspace vulnerability, whatever this user is. Selinux, chroot, cgroups/containerization add a layer of protection to this, but any vulnerability that bypass these will be as exploitable from nobody as from any other local user. It will protect a user files from some access attempts but will fail to prevent any serious attack. And as usual when it comes to security, a false sense of security is worse than no security at all.
Remember that some exploits exist that can climb outside of a full-blown virtual machine to the virtualisation host, finding a user escalation vulnerability is even more likely.
The only real protection is an up-to-date system, sane user behavior and maybe a little bit of paranoia.