Help my Linksys WRT54G router was broken into using the "curl" command

Discussion in 'Computer Security' started by Debbie Hurley, Jul 4, 2007.

  1. It's way too easy to break into the Linksys WRT54G router!

    Instantly bypassing the administrator password, my fifteen-year old
    neighbor broke into my Linksys WRT54G router (firmware revision v1.0.0.6)
    in ten seconds simply by sending this one "curl" command to it via the
    Internet from his home next door!

    c:\> curl -d "SecurityMode=0&layout=en"

    This kid was kind enough to knock on my door today to tell me to fix it.

    I invited him in, and from inside my own house, he showed me the Linksys
    WRT54G command above which immediately disabled all my wireless security
    WITHOUT him having to enter any password!

    He showed me how to disable remote administration but he said the
    vulnerability still exists until I get a new router. I can't believe
    everyone with a Linksys WRT54G router is throwing it in the garbage.

    Where/how can I find a firmware update that protects me from this
    Debbie Hurley, Jul 4, 2007
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  2. Debbie Hurley

    kev Guest

    Unless I am getting old then if he posted this command via the Internet
    it would have got him nowhere. The curl -d command would post the data
    to which is not a public IP address available on the
    Internet and would have have given him a timeout, unless his router
    address is
    For him to use this command on your computer implies you are using a
    Linux distribution and have installed curl and should know what it is
    capable of doing.
    kev, Jul 4, 2007
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  3. Debbie Hurley

    Larry Finger Guest

    With the IP Address changed to, my WRT54G returned "curl: (52) Empty reply from server"
    and encryption was still on. Using, it timed out. I don't know what is different with
    your system, but it seems not to be a general problem.

    Larry Finger, Jul 4, 2007
  4. Debbie Hurley

    kev Guest

    The Firmware V suggests they are playing with the Version 5
    router which used Vxworks, so I don't know what the commands were for
    that and I can't really be bothered to search for them.
    kev, Jul 4, 2007
  5. Debbie Hurley

    Leythos Guest

    While I've not verified it, you should have googled for basic security
    methods and you would have found that you need to change the default
    subnet to something else, keeping the 192.168.0, which is the default,
    is always a bad idea.

    192.168.0 and 192.168.1 are common default subnets for home routers,
    don't use them.

    Leythos - (remove 999 to email me)

    Learn more about PCBUTTS1 and his antics and ethic and his perversion
    with Porn and Filth. Just take a look at some of the FILTH he's created
    and put on his website:
    3rd link shows what he's exposed to children (the link I've include does
    not directly display his filth). You can find the same information by
    googling for 'PCBUTTS1' and 'exposed to kids'.
    Leythos, Jul 4, 2007
  6. I called him about this just now. He said there were two easy ways to wipe
    out the security of any Linksys WRT54G router without having to enter any
    log in information by taking advantage of Linksys widespread "access
    control error" vulnerabilities.

    The first was to access my router by it's IP address and then to do a
    remote configuration into the router that way. I had the remote
    configuration enabled so he showed me how to disable that in the router so
    the average person wouldn't disable my router security from half way around
    the world. He says it definately can be done remotely and said he'd mail me
    the instructions. He ended with saying that anyone who says it can't be
    done doesn't know what they're talking about. I'll wait for his
    instructions before I go any further on that.
    Debbie Hurley, Jul 4, 2007
  7. Debbie Hurley

    Todd H. Guest

    Among the reasons having wireless security disabled and letting
    neighbors join your local network for free is a bad idea.

    or... use third party firmware such as
    Todd H., Jul 4, 2007
  8. No. He showed me how to do it on my OWN Windows computer.
    All he did was download curl from and put
    the windows binary into my c:\os\winxp\system32\curl.exe location.

    He told me curl works on just about every operating system in the world,
    and from the looks of the web page above, it sure looks like it.

    When I type Start cmd and then curl, I get a response of:
    Microsoft Windows XP [Version 5.1.2600]
    (C) Copyright 1985-2001 Microsoft Corp.

    C:\My Stuff\Documents and Settings\debbie>curl
    curl: try 'curl --help' or 'curl --manual' for more information
    Debbie Hurley, Jul 4, 2007
  9. Debbie Hurley

    Todd H. Guest

    I meant to paste this vulnerability of v5 wrt54g's here:

    Linksys WRT54GS POST Request Configuration Change Authentication
    Bypass Vulnerability

    It's a known issue. The fix is to upgrade firmware per the link
    And I'd have a chat with the parents of the kid, thanking him for
    bringing the issue to your attention, but alwso warning him that his
    "gray hat" actitivities can get him sent to jail, despite being well

    You don't "test" stuff you don't own or are engaged to test with
    written legal permission of the owner.

    Some news stories to drive the point home:

    Best Regards,
    Todd H., Jul 4, 2007
  10. I just grabbed my horrified notes from yesterday.

    Try this which is the simplified test my neighbor wrote down for me when he
    showed it to me yesterday - and let us know if it disables your Linksys
    WRT54G router security without asking for a password.

    1. Assume the vulnerable WRT54G Linksys router (mine is v5 v1.0.0.6).
    2. Connect a yellow wire from the router to the computer
    3. Install curl on Windows XP from
    4. Add curl to your path (or put it in system32)
    5. Start Run cmd telnet 80
    6. Enter the web command to disable wireless security
    POST /Security.tri
    7. Look at your router to see you now have NO SECURITY!

    He said the only reason we used the wire was to make it easier to show me.
    He even did it wirelessly while out on my driveway outside my house. He
    said ANYONE could do it from the Internet if they knew my IP address.
    Luckily, he said nobody knows my IP address. Whew!

    I didn't realize using a Linksys WRT54G router was so dangerous!
    Debbie Hurley, Jul 4, 2007
  11. On the bottom of the Linksys WRT54G router it says it's version 5.

    My neighbor has been sending me emails as I told him about this thread.
    He says it happens with a lot of versions, his being a Linksys WRT54g home
    router, firmware revision 1.00.9 and he says all his friends' routers are
    similarly vulnerable which he called the "GENERIC-MAP-NOMATCH"
    Debbie Hurley, Jul 4, 2007
  12. My neighbor says what you said above is totally wrong in that it doesn't
    matter what IP address I use because he uses something called winpcap to
    snair the router IP address off the air!

    He says he gets an "ARP" from a program called ethereal which tells him all
    the "who" and "tell" arp commands which tells him every router's IP address
    in the neighborhood. So he called it 'smoke and mirrors' to change my IP

    That's why he suggested I find a patch to the Linksys WRT54G
    GENERIC-MAP-NOMATCH vulnerability.

    By the way, he said there are more than one vulnerabilities. I asked him to
    show me in writing and he just sent me something which I'll post to you
    once I clean it up a bit.
    Debbie Hurley, Jul 4, 2007
  13. Old bugs never die. They just get reposted:
    Note the dates from about a year ago. This was fixed with a firmware
    update to the v5/v6 hardware mutation router with v1.01.0. The
    current version is v1.02.0. Please download, install, and retest.

    All the routers I have handy are running DD-WRT v23 SP2 and SP3. The
    curl trick doesn't work on any of them from either Ubuntu 6.10 or
    Cygwin 1.5.xx on W2K.

    You must really be concerned as you also posted the comment to the
    Linksys Forums at:
    Nice kid. Be sure to thank him. If you're in the computah biz, hire
    If he's doing it from the LAN side, that's cheating a bit. In order
    to do the same thing from the WAN side, your router would need to have
    remote admin enabled, which is disabled by default. Note the default
    If remote admin was enabled, someone has been tinkering with the
    default setup.

    Incidentally, all the router manufacturers, except 2Wire ship their
    routers not very secure by default. If you simply plugged the router
    in straight out of the box, you have a wide open system, with well
    know passwords, and an invitation for problems. I've been trying to
    get various manufacturers to change their evil ways and start shipping
    routers that require the user to setup:
    1. A suitable router password
    2. A unique SSID
    3. A reasonable WPA-PSK encryption key
    The wireless would be disabled until this is done. None of them want
    to do this for fear that it would diminish your "out of box
    I've been tempted quite often as there are plenty of other things I
    detest about the WRT54G/GS v5 and v6 mutations. The general lack of
    RAM and NVRAM are my biggest gripe, which make loading alternative
    firmware a PITA. v5 and v6 routers also tend to lockup and hang for
    no obvious reason. The inability to simultaneously connect more than
    a few clients:,com_chart/Itemid,189/chart,124/
    (see bottom of chart) in v5 and v6 also sucks. Yeah, it's a terrible
    router. If you're planning on recycling yours, please mail it to the
    address in my .signature.
    The kid didn't tell you this? First he breaks in. He leaves remote
    admin turned on so he can break in again. Then he shows you how it
    works, but doesn't tell you how to fix it? Is he selling wireless
    routers door to door? Smart kid.

    Perhaps you should try the Linksys support web pile:
    Your WRT54G hardware mutation number is on the serial number tag on
    the bottom of the router.
    Jeff Liebermann, Jul 4, 2007
  14. But, he showed me it works while WIRED to my vulnerable Linksys WRT54G
    router! He said the GENERIC-MAP-NOMATCH vulnerability has nothing to do
    with wireless. It's inherent in the Linksys WRT54G router unfortunately!

    Here is his email talking about TWO vulnerabilities in the Linksys WRT54G

    "You have two problems. The first is the password validation for
    configuration settings is not needed for your Linksys WRT54G router and the
    second is that with java turned on any web site anywhere can force a
    request to the linksys router, and the router will accept the request."

    He also sent me a 2600 web address explaining the whole thing but I didn't
    understand it at all.
    Debbie Hurley, Jul 4, 2007
  15. Here is a forwarded email which explains the severe Linksys WRT54G
    vulnerability I'm afraid. It looks like this vulnerability which allows any
    web site to disable your browser security has been around for a long time
    based on the time stamps of the email!


    Date: Fri, 04 Aug 2006 14:00:01 +0000
    From: "Ginsu Rabbit" <>
    Subject: [Full-disclosure] linksys WRT54g authentication bypass

    I'm having some trouble believing this hasn't been reported before. If you
    have a linksys router handy, please check to see whether it is vulnerable
    to this attack. It's possible that all of the linksys router web UIs have
    the same bug. Hopefully the problem is isolated to one particular model or
    firmware revision.


    Tested product: Linksys WRT54g home router, firmware revision 1.00.9.

    Problem #1: No password validation for configuration settings.

    The WRT54g does not attempt to verify a username and password when
    configuration settings are being changed. If you wish to read
    configuration settings, you must provide the administrator ID and password
    via HTTP basic authentication. No similar check is done for configuration

    This request results in a user-id and password prompt:
    GET /wireless.htm

    This request disables wireless security on the router, with no password
    POST /Security.tri
    Content-Length: 24


    Problem #2: Cross-site request forgery

    The web administration console does not verify that the request to change
    the router configuration is being made with the consent of the
    administrator. Any web site can force a browser to send a request to the
    linksys router, and the router will accept the request.

    II. Exploitation

    The combination of these two bugs means that any internet web site can
    change the configuration of your router. Recently published techniques for
    port-scanning and web server finger printing via java and javascript make
    this even easier. The attack scenario is as follows:

    - intranet user visits a malicious web site
    - malicious web site returns specially crafted HTML page
    - intranet user's browser automatically sends a request to the router that
    enables the remote administration interface
    - the owner of the malicious web site now has complete access to your

    I'm not going to share the "specially crafted HTML page" at this time, but
    it isn't all that special.


    If your router is vulnerable, the following curl command will disable
    wireless security on your router. Tests for other router models and
    firmware revisions may be different:

    curl -d "SecurityMode=0&layout=en"


    1) Make sure you've disabled the remote administration feature of your
    router. If you have this "feature" enabled, anybody on the internet can
    take control of the router.

    2) Change the IP address of the router to a random value, preferably in the
    range assigned to private networks. For example, change the IP address to
    10.x.y.z, where x, y, and z are numbers between 0 and 255 inclusive. This
    makes it more difficult for an attacker to forge the request necessary to
    change the router configuration. This mitigation technique might not help
    much if you have a java-enabled browser, because of recently published
    techniques for determining gateway addresses via java applets.

    3) Disable HTTP access to the administration interface of the router,
    allowing only HTTPS access. Under most circumstances, this will cause the
    browser to show a certificate warning before the configuration is changed.


    Linksys customer support was notified on June 24, 2006.
    Full disclosure on August 4, 2006
    Debbie Hurley, Jul 4, 2007
  16. Debbie Hurley

    Warren Oates Guest

    Warren Oates, Jul 4, 2007
  17. Hi Jeff!
    Yes. I am really concerned. And scared that it takes all of ten seconds to
    break into my router by a fifteen year old cute kid who mows my lawn every
    month. I believ him when he says I need to upgrade my router. You are the
    only one here who believed me. Thank you. Thank you. Thank you. For a
    moment, I thought I was going crazy when the "experts" were telling me what
    I saw I didn't see. I felt like I was being persecuted for reporting this.
    I didn't realize that the Linksys WRT54G router I bought was so weak. Why
    didn't Linksys TELL me about this in the package? I have never updated my
    "firmware" before. Can you hand hold my hands a bit to tell me how to do
    it. I don't want to ruin the router.

    I'll first read everything I can find on updating the router and then post
    back if I ruin it doing so. I can read well but I don't know how to debug
    once I hit a problem. But I keep trying and that's why I'm here taling to

    Thank you - I love your post the best because I was beginning to wonder why
    nobody else knew about this which seemed pretty bad that it took all of ten
    seconds to wipe out all my hardware security.

    BTW, my neighbor said to change my IP address and the hostname and media
    address of my router and pc constantly because that's what he used to
    figure out which was mine in the neighborhood. Is there a way to change the
    router & PC hostname and media name automatically every day or do I have to
    do it manually every day to be safe?
    Debbie Hurley, Jul 4, 2007
  18. One thing I'd like to do is change the login name!
    I asked on the linksys forums and will check to see if there is a way to
    change the login name from just a dumb blank stare to something interesting
    so others can't get in so easily through the front door of the router.

    I will also read up on how to upgrade the firmware of my router using your
    links. Thanks. I love you!
    Debbie Hurley, Jul 4, 2007
  19. What I don't get is why the Linksys WRT54G router has a password but not a
    login name. Wouldn't it be MORE SECURE if I could change the login name?

    I can type anything I want into the login name field but it doesn't take.

    Am I doing something wrong?

    Why does the Linksys v5 WRT54G router have a login name if it isn't used?
    Likewise with the host name. Why does it have a host name that isn't used
    and why can't I just set the hostname to a blank.

    It seems topsy turvy to me. Am I wrong?
    Debbie Hurley, Jul 4, 2007
  20. Debbie Hurley

    Todd H. Guest

    This is among the reasons you only let trusted parties on your LAN if
    at all possible.

    IIRC, it requires LAN access to exploit unless you are running a
    non-default configuration whereby remote admin is enabled.

    It pertains to wireless insofar as if you don't have wireless security
    enabled, then any old neighbor can join to your LAN and then exercise
    the vulnerability.
    Todd H., Jul 4, 2007
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