Add /usr/sbin and /sbin to default root PATH When dropbear is used in a very restricted environment (such as in a initrd), the default user shell is often also very restricted and doesn't take care of setting the PATH so the user ends up with the PATH set by dropbear. Unfortunately, dropbear always sets "/usr/bin:/bin" as default PATH even for the root user which should have /usr/sbin and /sbin too. For a concrete instance of this problem, see the "Remote Unlocking" section in this tutorial: https://paxswill.com/blog/2013/11/04/encrypted-raspberry-pi/ It speaks of a bug in the initramfs script because it's written "blkid" instead of "/sbin/blkid"... this is just because the scripts from the initramfs do not expect to have a PATH without the sbin directories and because dropbear is not setting the PATH appropriately for the root user. I'm thus suggesting to use the attached patch to fix this misbehaviour (I did not test it, but it's easy enough). It might seem anecdotic but multiple Kali users have been bitten by this. From https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903403

/*	$OpenBSD: sshpty.h,v 1.4 2002/03/04 17:27:39 stevesk Exp $	*/

/*
 * Copied from openssh-3.5p1 source by Matt Johnston 2003
 *
 * Author: Tatu Ylonen <[email protected]>
 * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
 *                    All rights reserved
 * Functions for allocating a pseudo-terminal and making it the controlling
 * tty.
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 */

#ifndef SSHPTY_H
#define SSHPTY_H

int	 pty_allocate(int *, int *, char *, int);
void	 pty_release(const char *);
void	 pty_make_controlling_tty(int *, const char *);
void	 pty_change_window_size(int, int, int, int, int);
void	 pty_setowner(struct passwd *, const char *);

#endif /* SSHPTY_H */