Attacking Linksys WRT160N router using the "URL Obfuscation in Frames" bug

Attacking Linksys WRT160N router using the "URL Obfuscation in Frames" bug

Posted on August 26, 2010 by Roberto Salgado

Security Researcher Aditya K Sood from Armorize Technologies recently reported a bug that many criticized as being bogus ( To keep the explanation brief, previously phishers could confuse non-technical users by making them open a URL such as http://[email protected], making the user believe they were visiting when in reality they were being taken to Ever since, browsers have added a confirmation dialog, warning the user what site they are really accessing. This confirmation dialog, however, is not used in subresources such as iFRAMES since the URL is not visible unless you view the source-code. Although this "bug" is obviously not useful for obfuscation, as Sood claims, we can still use it to attack routers that use the default password.

In my case, I'm using a Linksys WRT160N router and an XSS vulnerability reported by David Gil back in 2008. This PoC enables remote administration on the victim's router just by having the victim visit a malicious website. The nice thing about this bug is that Firefox/Chrome won't alert the victim that they're being logged in to their router, so the whole attack is transparent to the user.

<iframe src='http://admin:admin@
%3C%2Fscript%3E' style="display:none;"/>

Firefox and Chrome will execute the attack without prompting the user, Opera on the other hand, gives a warning and blocks intranet requests by default. Mozilla stated that they're not planning on fixing this bug, since they don't believe there is an attack vector. Although the risk may be considered minimal, it still provides a way for attackers to abuse XSS, CSRF vulnerabilities on pages that require authentication. Considering that most users don't change their routers default password and that most router vendors don't take the time to fix these vulnerabilities as they don't see them is a big threat, I believe a warning dialog wouldn't hurt.

Latest Blog Entries

Belkin Wemo Switch NMap Scripts
Belkin Wemo Switch Smart Plug is a network controlled power outlet. The current firmware version does not requiere authentication to switch the power ON or OFF or to gather information such as nearby wireless networks. Two NMap scripts have been published

Downloading an Application's Entire Source Code Through an Exposed GIT Directory
Website administrators sometimes inadvertently leave an exposed .git directory, from which it is possible to download the entire source code of the web application using just wget and a common server misconfiguration.

credmap: The Credential Mapper
An overview of credmap, an open source penetration testing tool that automates the process of testing for credential reuse. It does so by testing supplied user credentials on known websites and verifies if the password has been reused on any of these.

Latest News

Blackhat EU 2015
Websec participated with two tools at the Blackhat, EU Arsenal held in Amsterdam, NL from the 10-13 of November, 2015. During this event, we introduced our brand new tool "credmap: The Credential Mapper" and also presented an amped-up version of Panoptic.

BSides Vancouver 2015
Websec is proud to announce that we will be attending the 3rd annual edition of BSides Vancouver, a local non-profit information security conference held in the heart of Vancouver, BC on March 16 and 17.