Netgear, Linksys and many other Wireless Routers have a backdoor

Pierluigi Paganini January 04, 2014

The French hacker Eloi Vanderbeken discovered the presence of a backdoor in principal models of routers including Netgear, Linksys and Cisco.

The presence of a backdoor in the commercial routers it is no more a surprise, we found flawed firmware in the popular D-Link in the past and now it seem that a similar problem affects Netgear and Linksys Wireless Routers.

Both categories of devices have a backdoor that allows an attacker to reset the admin panel password to defaults, the discovery was made by Eloi Vanderbeken, a French engineer that has found the administration password Reset vulnerability in many Netgear and Linksys Routers.

He has provided all the materials of his research on GitHub to allow other colleagues to make further analysis.

During last Christmas Holidays the hacker forgot the admin interface password of his Linksys WAG200G router so he decided to scan it to try to find a flaw and gain access back of its administration panel. He found a suspicious open TCP port i.e. 32764, this was the beginning of his analysis because he decided to make a reverse-engineering of the Linksys firmware.

Surprise! The code contains a secret backdoor interface that allowed him to send commands to the Linksys router from a command-line shell without being authenticated as the administrator.

Eloi tried to brute-force the authentication on the suspicious port after reset the Linksys router to the to factory settings with default router administration username and password.


Linksys backdoor brute force

The exploit script written in Python can be downloaded on GitHub,  be aware the backdoor is not exploitable remotely, but anyway it represent a serious security hole for the analyzed Linksys router.

“The backdoor requires that the attacker be on the local network, so this isn’t something that could be used to remotely attack DSL users. However, it could be used to commandeer a wireless access point and allow an attacker to get unfettered access to local network resources.”

Linksys backdoor brute force 2
Many other hackers have made a similar research after the Eloi’s discovery, consider that these routers are manufactured by Sercomm, this means that Cisco, Watchguard, Belkin and many other network devices are backdoored.  The Complete List of surely affected routers is:

  • Linksys WAG200G
  • Netgear DM111Pv2 (
  • Linksys WAG320N (
  • Linksys WAG54G2 (
  • DGN1000[B] Netgear N150 (
  • NETGEAR DGN1000 (don’t know if there is a difference with the others N150 ones…
  • Netgear DG834G V2 firmware 4.01.40 (thanks Burn2 Dev)
  • Diamond DSL642WLG / SerComm IP806Gx v2 TI (
  • Linksys WAG120N (
  • Cisco WAP4410N (
  • Linksys WAG160n (
  • LevelOne WBR3460B (
  • Netgear DGN3500 (
  • NetGear DG834 v3 (thanks jd)
  • Netgear DG834[GB, N, PN] version < 5 (
  • Netgear DGN2000B (
  • Linksys WRVS4400N (Firmware Version:V2.0.2.1) (
  • Lynksys WRT300N fw 2.00.17 (
  • NETGEAR JNR3210 (

but it could be longer, many other devices are under investigation.

Bad news, my router contains a backdoor too ;-(

Pierluigi Paganini

(Security Affairs –  Linksys routers, backdoors)

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