wiki/en/research-security.md

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Alternative way to get access to full working system.

You will not have original root pass but you will be able get into :)

Limited shell access

TESTED on GOKE SOC. over the UART interface it is possible to get into a limited shell, but this shell does not load full working system.

setenv bootargs ${bootargs} single init=/bin/sh
boot

Once we are in limited shell it is need to mount ROM filesystem:

mount -t jffs2 /dev/mtdblock3 /rom

Also will be great to mount sd card to copy some files:

mount
mount -a
mount /dev/mmcblk0p1 on /mnt/s0

Modifying the file system

on /rom filesystem you can edit the /room/etc/passwd file but once the device restarts it will be set to default, this happens because there is a guide bin file writing to passwd file on each start, so we need to modify this executable.

copy system.dat to sd card

cp /rom/system.dat /mnt/s0

on a linux computer it is need to unsquahfs system.dat, do some changes and resquashfs:

mkdir squashfs-temp
cd squashfs-temp

unsquashfs system.dat

find guide file and hexedit to modify where "/etc/passwd" is written and change one letter, for example "/etc/passwT". This file will be created on start instead of passwd replaced.

re squash the file system:

mksquashfs ./squashfs-root ./file -comp xz -no-xattrs -noappend -no-exports -all-root -quiet -b 131072

and copy back from sd card to /rom directory on goke soc.

now you can edit /rom/etc/passwd with your own pass, and when you restart the device you will have full working system with your own pass.