[NEWS] SMC Routers Passwordless Remote Administration

Type securityvulns
Reporter Securityvulns
Modified 2004-05-11T00:00:00


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SMC Routers Passwordless Remote Administration


Several <http://www.smc.com/> SMC Routers does not close the remote administration port to external users (i.e. from the Internet), nor does it require any authentication. A malicious attacker can obtain complete control over the router, thus exposing the LAN.


Vulnerable Systems: * SMC Router 7008ABR (part number 750.9814 with firmware 1.032) * SMC Router 7004VBR (version 1, firmware 1.231) * Others models and firmware versions may be vulnerable.

SMC broadband routers ship with remote administration enabled by default on their port 1900 on the WAN side of the router. If you just pull one out of the box, plug it into your Internet connection and go through the "Setup Wizard" then don't do anything beyond that point, port 1900 is open on the router and completely passwordless, allowing ANY person to just visit where "" is the router's external IP address and hit "Login" and have full control of the router. This may allow any person to expose the very machines being protected by the router.

Steps to reproduce: 1. Reset the router to factory defaults, either by logging onto its remote administration page at and clicking "Advanced Setup" then "Tools" then "Configuration Tools" then choose "Restore barricade to factory defaults" and click "Next." Or by holding down the router's reset button with a paper clip for 30 seconds. 2. After the router has been reset to factory defaults, visit its administration page at 3. Click "login" 4. Click "Setup Wizard" then "Next" 5. Choose the appropriate connection type you have. 6. When it is "connected" and you can web browse on the Internet just fine behind it, go back to the router's administration page at 7. Click "Advanced Setup" then "Status" and write down the router's WAN IP address. (For example 8. Now using a computer that has a different external IP address (another machine on the Internet), visit the router's port 1900 in your web browser

You are then greeted with a login prompt. Click "Login" and you have full control of the router remotely. While you are there, click "Advanced Setup" and then "System" then "Remote Management" and you can verify "Remote Management" is supposedly disabled yet somehow you are remotely managing the device.

Workarounds: 1. Enable the router's firewall in its "Advanced Setup". Or: 2. Forward port 1900 of the router to a non-existent internal IP address (such as if it isn't in use).


The information has been provided by <mailto:user86@earthlink.net> user86.


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