Hello list!

There are Brute Force and Cross-Site Request Forgery vulnerabilities
in TP-Link TL-WR940N and TL-WR941ND. After my advisory about
vulnerabilities in TP-Link TL-WR841N and TL-WR841ND in 2017.

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Affected products:
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Vulnerable are the next models: TP-Link TL-WR940N and TL-WR941ND,
Firmware Version 3.16.9 Build 151216. All other versions also must be
vulnerable. I informed TP-Link about vulnerabilities in different
their devices since 2017, but there were no answers from vendor.

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Details:
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Brute Force (WASC-11):

http://192.168.0.1

No protection from BF attacks in login form. By default access from
Internet is closed, so it's possible to pick up password only via LAN.
But via CSRF attacks it's possible to open remote access.

Cross-Site Request Forgery (WASC-09):

In section Remote Control.

Turn off access via
Internet:http://192.168.0.1/YVNLOORCJBATZQDB/userRpm/ManageControlRpm.htm?port=80&ip=0.0.0.0&Save=1

Turn on access via
Internet:http://192.168.0.1/YVNLOORCJBATZQDB/userRpm/ManageControlRpm.htm?port=80&ip=255.255.255.255&Save=1

For protection bypass it's needed to set Referer header and path
(YVNLOORCJBATZQDB), that changes every time at login to admin panel.
This path can be found through information leakage, social engineering
or XSS vulnerabilities in admin panel. In old versions there is no
such protection, so it's easy to conduct this and other CSRF attacks.

Cross-Site Request Forgery (WASC-09):

Logout from admin panel via request to page http://192.168.0.1.

<img src="http://192.168.0.1">

I mentioned about these vulnerabilities at my site
(http://websecurity.com.ua/8407/).

Best wishes & regards,
Eugene Dokukin aka MustLive
Administrator of Websecurity web site
http://websecurity.com.ua