Date: Tue, 23 Feb 2010 22:20:53 +0000
From: "Adrian P." <ap@...citizen.org>
To: Gadi Evron <ge@...uxbox.org>
Cc: funsec <funsec@...uxbox.org>, full-disclosure@...ts.grok.org.uk,
	"bugtraq@...urityfocus.com" <bugtraq@...urityfocus.com>
Subject: Re: Chuck Norris Botnet and Broadband Routers

It's no secret that there are tons of broadband routers/modems with
exposed admin interfaces (HTTP/SSH/Telnet/whatever) using default/weak
credentials.

While the Chuck Norris botnet is interesting in that it shows that the
problem is real, it shouldn't surprise anyone who has researched the
security of broadband embedded devices.

It's also not the first time an incident of this nature has happened.
I'm sure a lot of the list readers remember the mass-phishing attack
launched November 2007 [1] against several popular 2Wire broadband
routers in Mexico. The attack was accomplished by means of changing
the router's DNS settings via a CSRF hole on the web interface.

A similar issue used to exist on the BT Home Hub and was reported in
October 2007 [2] (a month earlier) where it was possible to compromise
the router by tricking a user to visit a malicious page. The payload
[3] would then exploit an authentication bypass and CSRF vulnerability
in order to enable the "remote assistance" feature. (The intended
purpose of this feature was to allow BT engineers to remotely
troubleshoot home routers.) The attacker could then login remotely to
the router with admin privileges using a password of his choice (set
in the actual exploit payload).

And of course there is the infamous BeThere backdoor admin account
reported in February 2007 which you mentioned in your article [4].

The security of home-grade embedded devices has a long way to go. I
think that the home router hacking challenge [5] [6] confirmed this by
showing that many of these devices are affected by serious
vulnerabilities, many of which are trivially exploitable.

I couldn't agree more that ISPs do need to take responsibility and
ensure that new modem/router builds are audited for common security
issues before being distributed to their broadband customers.


ap

[1] http://www.hispasec.com/unaaldia/3313
[2] http://www.gnucitizen.org/blog/bt-home-flub-pwnin-the-bt-home-hub/
[3] http://www.gnucitizen.org/blog/bt-home-flub-pwnin-the-bt-home-hub-4/
[4] http://blogs.securiteam.com/index.php/archives/826
[5] http://www.gnucitizen.org/projects/router-hacking-challenge/
[6] http://marc.info/?l=bugtraq&m=120441195905480&w=2

On Mon, Feb 22, 2010 at 2:22 PM, Gadi Evron <ge@...uxbox.org> wrote:
> Last week Czech researchers released information on a new worm which
> exploits CPE devices (broadband routers) by means such as default passwords,
> constructing a large DDoS botnet. Today this story hit international news.
>
> Original Czech:
> http://praguemonitor.com/2010/02/16/czech-experts-uncover-global-virus-network
>
> English:
> http://www.pcworld.com/businesscenter/article/189868/chuck_norris_botnet_karatechops_routers_hard.html
>
> When I raised this issue before in 2007 on NANOG, some other vetted mailing
> lists and on CircleID, the consensus was that the vendors will not change
> their position on default settings unless "something happens", I guess this
> is it, but I am not optimistic on seeing activity from vendors on this now,
> either.
>
> CircleID story 1:
> http://www.circleid.com/posts/broadband_routers_botnets/
>
> CircleID story 2:
> http://www.circleid.com/posts/broadband_router_insecurity/
>
> The spread of insecure broadband modems (DSL and Cable) is extremely
> wide-spread, with numerous ISPs, large and small, whose entire (read
> significant portions of) broadband population is vulnerable. In tests Prof.
> Randy Vaughn and I conducted with some ISPs in 2007-8 the results have not
> been promising.
>
> Further, many of these devices world wide serve as infection mechanisms for
> the computers behind them, with hijacked DNS that points end-users to
> malicious web sites.
>
> On the ISPs end, much like in the early days of botnets, many service
> providers did not see these devices as their responsibility -- even though
> in many cases they are the providers of the systems, and these posed a
> potential DDoS threat to their networks. As a mind-set, operationally taking
> responsibility for devices located at the homes of end users made no sense,
> and therefore the stance ISPs took on this issue was understandable, if
> irresponsible.
>
> As we can't rely on the vendors, ISPs should step up, and at the very least
> ensure that devices they provide to their end users are properly set up (a
> significant number of iSPs already pre-configure them for support purposes).
>
> The Czech researchers have done a good job and I'd like to thank them for
> sharing their research with us.
>
> In this article by Robert McMillan, some details are shared in English:
>
> ----------
> Discovered by Czech researchers, the botnet has been spreading by taking
> advantage of poorly configured routers and DSL modems, according to Jan
> Vykopal, the head of the network security department with Masaryk
> University's Institute of Computer Science in Brno, Czech Republic.
>
> The malware got the Chuck Norris moniker from a programmer's Italian comment
> in its source code: "in nome di Chuck Norris," which means "in the name of
> Chuck Norris." Norris is a U.S. actor best known for his martial arts films
> such as "The Way of the Dragon" and "Missing in Action."
>
> Security experts say that various types of botnets have infected millions of
> computers worldwide to date, but Chuck Norris is unusual in that it infects
> DSL modems and routers rather than PCs.
>
> It installs itself on routers and modems by guessing default administrative
> passwords and taking advantage of the fact that many devices are configured
> to allow remote access. It also exploits a known vulnerability in D-Link
> Systems devices, Vykopal said in an e-mail interview.
>
> A D-Link spokesman said he was not aware of the botnet, and the company did
> not immediately have any comment on the issue.
>
> Like an earlier router-infecting botnet called Psyb0t, Chuck Norris can
> infect an MIPS-based device running the Linux operating system if its
> administration interface has a weak username and password, he said. This
> MIPS/Linux combination is widely used in routers and DSL modems, but the
> botnet also attacks satellite TV receivers.
> ----------
>
> Read more here:
> http://www.pcworld.com/businesscenter/article/189868/chuck_norris_botnet_karatechops_routers_hard.html
>
> I will post updates on this as I discover them on my blog, under this same
> post, here:
> http://gadievron.blogspot.com/2010/02/chuck-norris-botnet-and-broadband.html
>
>        Gadi.
>



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