AppArmorJail1
Beschreibung
Attention : this CTF-ATD is linked to the challenge "AppArmor Jail - Introduction"
When connecting to the administrator’s server, a restricted shell via an AppArmor policy prevents you from reading the flag even though you are the owner...
Find a way to read the flag at any cost and override the AppArmor policy in place which is configured as follows:
#include <tunables/global>
profile docker_chall01 flags=(attach_disconnected,mediate_deleted) {
#include <abstractions/base>
network,
capability,
file,
umount,
signal (send,receive),
deny mount,
deny /sys/[^f]*/** wklx,
deny /sys/f[^s]*/** wklx,
deny /sys/fs/[^c]*/** wklx,
deny /sys/fs/c[^g]*/** wklx,
deny /sys/fs/cg[^r]*/** wklx,
deny /sys/firmware/** rwklx,
deny /sys/kernel/security/** rwklx,
deny @{PROC}/* w, # deny write for all files directly in /proc (not in a subdir)
# deny write to files not in /proc/<number>/** or /proc/sys/**
deny @{PROC}/{[^1-9],[^1-9][^0-9],[^1-9s][^0-9y][^0-9s],[^1-9][^0-9][^0-9][^0-9]*}/** w,
deny @{PROC}/sys/[^k]** w, # deny /proc/sys except /proc/sys/k* (effectively /proc/sys/kernel)
deny @{PROC}/sys/kernel/{?,??,[^s][^h][^m]**} w, # deny everything except shm* in /proc/sys/kernel/
deny @{PROC}/sysrq-trigger rwklx,
deny @{PROC}/kcore rwklx,
/home/app-script-ch27/bash px -> bashprof1,
}
profile bashprof1 flags=(attach_disconnected,mediate_deleted) {
#include <abstractions/base>
#include <abstractions/bash>
network,
capability,
deny mount,
umount,
signal (send,receive),
deny /sys/[^f]*/** wklx,
deny /sys/f[^s]*/** wklx,
deny /sys/fs/[^c]*/** wklx,
deny /sys/fs/c[^g]*/** wklx,
deny /sys/fs/cg[^r]*/** wklx,
deny /sys/firmware/** rwklx,
deny /sys/kernel/security/** rwklx,
deny @{PROC}/* w, # deny write for all files directly in /proc (not in a subdir)
# deny write to files not in /proc/<number>/** or /proc/sys/**
deny @{PROC}/{[^1-9],[^1-9][^0-9],[^1-9s][^0-9y][^0-9s],[^1-9][^0-9][^0-9][^0-9]*}/** w,
deny @{PROC}/sys/[^k]** w, # deny /proc/sys except /proc/sys/k* (effectively /proc/sys/kernel)
deny @{PROC}/sys/kernel/{?,??,[^s][^h][^m]**} w, # deny everything except shm* in /proc/sys/kernel/
deny @{PROC}/sysrq-trigger rwklx,
deny @{PROC}/kcore rwklx,
/ r,
/** mrwlk,
/bin/** ix,
/usr/bin/** ix,
/lib/x86_64-linux-gnu/ld-*.so mrUx,
deny /home/app-script-ch27/flag.txt r,
}- Start the CTF-ATD "AppArmorJail1"
- Connect via SSH to the machine on port 22222 (app-script-ch27:app-script-ch27)
- The challenge validation password is in the /home/app-script-ch27/flag.txt file
- The validation password of the CTF ATD is in the file /passwd
Zeit der Kompromittierung
4 Stunden
Betriebssystem
linux
176 Virtuals Environnements
