not necessarily. e.g. java runtimes can expose debugging ports when needed that operate on a custom protocol.

or you can just build gdb into the container and run the process under gdb, then attach to the tty.

or you can debug from the host system where the container's pid namespace is a descendant of the root namespace and the other namespaces can be accessed via /proc or unshare.

What I meant is having a remote debugger is as good as having a remote shell in terms of remote code execution.