TP-Link TL-WR740N Wireless Router Remote Denial Of Service Exploit

Title: TP-Link TL-WR740N Wireless Router Remote Denial Of Service Exploit
Advisory ID: ZSL-2013-5135
Type: Local/Remote
Impact: DoS
Risk: (2/5)
Release Date: 21.03.2013
The TL-WR740N is a combined wired/wireless network connection device integrated with internet-sharing router and 4-port switch. The wireless N Router is 802.11b&g compatible based on 802.11n technology and gives you 802.11n performance up to 150Mbps at an even more affordable price. Bordering on 11n and surpassing 11g speed enables high bandwidth consuming applications like video streaming to be more fluid.
The TP-Link WR740N Wireless N Router network device is exposed to a remote denial of service vulnerability when processing a HTTP request. This issue occurs when the web server (httpd) fails to handle a HTTP GET request over a given default TCP port 80. Sending a sequence of three dots (...) to the router will crash its httpd service denying the legitimate users access to the admin control panel management interface. To bring back the http srv and the admin UI, a user must physically reboot the router.
TP-LINK Technologies Co., Ltd. -
Affected Version
Firmware version: 3.16.4 Build 130205 Rel.63875n (Released: 2/5/2013)
Hardware version: WR740N v4 00000000 (v4.23)
Model No. TL-WR740N / TL-WR740ND
Tested On
Router Webserver
Vendor Status
[17.03.2013] Vulnerability discovered.
[18.03.2013] Contact with the vendor.
[18.03.2013] Auto-reply from the vendor, mail received.
[20.03.2013] No response from the vendor.
[21.03.2013] Public security advisory released.
[21.03.2013] Vendor responds asking more details.
[21.03.2013] Sent detailed information to the vendor.
[28.03.2013] Vendor fixes the vulnerability in a BETA firmware sent to ZSL.
[28.03.2013] Researcher verifies the fix, replying to the vendor.
[28.03.2013] Vendor releases firmware version TL-WR740N_V4_130322 (
Vulnerability discovered by Gjoko Krstic - <>
[21.03.2013] - Initial release
[22.03.2013] - Added reference [3], [4] and [5]
[23.03.2013] - Added reference [6], [7] and [8]
[28.03.2013] - Added vendor status and reference [9]
[27.05.2013] - Added reference [10]
Zero Science Lab