On: Is chroot a security feature?

[tinus_hn]

So what are these mystical ‘several ways’, preferably some that do not require root and not require proc mounted in the chroot?

[dividuum → tinus_hn]

I can think of ptrace() attach to other processes of the same user outside of the chroot environment and inject arbitrary code.

[theamk → dividuum]

In modern systems, ptrace requires root even if attaching to the same user. So this hole has been closed.