Re: several vulnerabilities present in Belkin wireless routers

[Ian Clelland <ian () veryfresh com>]

On Fri, Jul 15, 2005 at 04:37:10PM +0100, Steve Kemp wrote:
> On Fri, Jul 15, 2005 at 08:14:14AM -0000, m123303 () securityfocus com wrote:
>
> > The first problem is the existance of a default telnet backdoor
> > running on the usual 23/tcp port. From my experience, telnet
> > interfaces are NOT enabled by default in wireless routers but rather,
> > they usually need to be enabled from their administrative web
> > interfaces manually:
> >
> >
> > <Start of output>
> >
> > Starting nmap 3.75 ( http://www.insecure.org/nmap/ ) at 2005-06-06
> > 18:34 BST
> > Initiating SYN Stealth Scan against BelkinModem.Belkin (192.168.2.1)
>
>
>   The obvious question to ask here, is "Can the telnet service be
>  connected to from the WAN side?".
>
>   All the later content you present, whilst interesting, is of
>  less value if the attacker must be on the LAN side of the router.

I suspect that the router will not be found vulnerable from that side,
but the exploit becomes interesting again if users on the Wireless LAN
are granted the same level of trust as those on the wired LAN. None of
the wireless routers I've seen have made any distinction between those
two segments, and they all come with default administration passwords
(and no requirement for the user to change them).

Of course, this 'exploit' really looks like just another example of an
'insecure by default' consumer device, rather than an issue with the
firmware.

Regards,
Ian