Podman rootless containers: no root, but still a Copy Fail exploit

Developers who thought rootless containers in Podman were the holy grail of security might want to sit down. A researcher stumbled upon a funny (but not really) vulnerability called Copy Fail that allows an attacker inside a container to copy files out without proper permissions. Yes, that classic case of 'no root' not meaning 'no problem'.

The gist is that when copying files from a container to the host with podman cp, the process inside can manipulate the filesystem to swap the intended file with a symlink to sensitive data. It's a classic symlink attack, but in the context of rootless containers it's particularly spicy: we went through all that trouble to drop privileges, and yet here we are.

Podman devs are already aware and likely preparing a patch. Until then, don't copy files from untrusted containers without extra verification. Or, you know, just use regular root containers — at least you know who to blame.

METABYTE's take: We love rootless too, but trusting containers blindly is like leaving your keys in the lock and hoping burglars are honest. When developing, always consider attack vectors, even when you think you're safe.