Tag Archives: Network

Fiddler Script for Accept-Language Testing

It’s been a while since I’ve blogged about anything so it’s only fitting that I post about doing something fairly trivial. I say it’s trivial because Fiddler makes my job so gosh-darn easy!

I often find myself testing that web sites work in various other languages. In many cases, changing the Accept-Language for a site will do the trick and luckily Fiddler’s custom rules will let you do the trick. The software allows you to specify Japanese as an option under the Rules menu.

That said, simply testing one language isn’t usually enough. I’d find myself hitting CTRL+R to open the CustomRules.js file, editing the Accept-Language and waiting for another day before I’d need to do this again.

I got tired of this today and completely removed the single-instance Japanese support option from Fiddler. So I replaced this code:

    // Cause Fiddler to override the Accept-Language header 
    public static RulesOption("Request &Japanese Content")
    var m_Japanese: boolean = false;

With this code:

    // Cause Fiddler to override the User-Agent header with one of the defined values
    RulesString("&Accept-Languages", true) 
    RulesStringValue(0,"None", "")
    RulesStringValue(1,"German", "de")
    RulesStringValue(2,"English", "en")
    RulesStringValue(3,"Spanish", "es")
    RulesStringValue(4,"French", "fr")
    RulesStringValue(5,"Italian", "it")
    RulesStringValue(6,"Japanese", "ja")
    RulesStringValue(7,"Korean", "ko")
    RulesStringValue(8,"Dutch ", "nl")
    RulesStringValue(9,"Polish", "pl")
    RulesStringValue(10,"Portuguese (Brazil)", "pt-br")
    RulesStringValue(11,"Russian", "ru")
    RulesStringValue(12,"Swedish ", "sv")
    RulesStringValue(13,"Chinese (PRC)", "zh-cn")
    RulesStringValue(14,"Chinese (Taiwan)", "zh-tw")
    RulesStringValue(15,"en-us, fr-fr", "en-us, fr-fr")
    RulesStringValue(16,"ru-mo, de-at, zh-tw, fr", "ru-mo;q=1,de-at;q=0.9,zh-tw;q=0.8,fr;q=0.6")
    RulesStringValue(17,"&Custom...", "%CUSTOM%")
    public static var sAL: String = null;

And later in the file, I replaced this code:

if (m_Japanese) {
    oSession.oRequest["Accept-Language"] = "ja";

with this code:

// Accept-Language Overrides
if (null != sAL) {
    oSession.oRequest["Accept-Language"] = sAL; 

Now every time I open Fiddler, I can just select the language I want to use.


Beating the dead horse – Wireless networks again

I hate to keep beating a dead horse here, but I want to get my point across concerning wireless networking. Sans has now issued a paper about the basic insecurities of wireless. Check it out and at least use this paper as input for threat modeling your networks and wireless applications.

Friends Don’t Let Friends Use Wireless

It will never cease to amaze me how much people implicitly trust wireless connections. I see businesses from coffee shops to book stores offering free wireless connectivity in the hopes that people will stick around and spend money. This is a great idea for businesses, and the concept does work. However, I often wonder why you would so willingly trust this free service.

Imagine this scenario. You walk into your favorite Barnes & Noble book store to sip some coffee, eat some eclairs, and surf a bit. While surfing, you decide you want to check your hotmail account. You type in your usual “http://www.hotmail.com” as you always do. You then enter your username and password as you always do. “Login Failed? Huh?” You type it again “Username: eye_me_leet | password: h4x0r2u”… ” and just as quickly as the first response occurs, the same response comes back “Login Failed”. Thinking this may be a cache problem or just a bug with IE, you close your browser or perhaps reboot all together. You type in the site again aych-tee-tee-pee collon-slash-slash dub-dub-dub-dot-hotmail-dot-com [Enter]. But to your horror, as the pixels on the page change, they don’t turn to the standard looking hotmail screen, instead, these pixels spell words only a truly 1334 r00t *** would put on a site — “U’V b33n pwnt !”. What happened, other than some really bad clichC) leet-speak?

When you connected to the first access point, you didn’t realize you were connecting to someone else in the same room as you. They set up their very own wireless access point that acted as a proxy for the internet. This user was running Ethereal to sniff packets, but more importantly, he set up his own machine as the authority for hotmail.com. In doing so, you were directed to his mock site that simulated the look and feel of Hotmail. When you typed in your username and password, it didn’t go to hotmail to authenticate. Instead, it was captured by the “hacker” who immediately used your information to log into the real hotmail site and change your credentials. This hacker was at least kind enough to tell you that you were “had”. Your username and password may likely be the same across multiple services too. That same one you used for hotmail is most likely similar, if not the same as the one you are using on your windows machine. So the user then connects to your machine’s IP address and types in the same username / password information to gain access to administrative shares, read your documents or infect you with viruses. Alternatively, the hacker could read and send email from your box and perhaps use it to gain more information about where you do business, who you talk to and what kind of work (or play) you engage in. The possibilities are limitless and terrifying.

Remember this the next time you blindly walk into a business and connect to their network.

DoS through TCP sequence number vulnerability

SecurityFocus is reporting that multiple vendors are affected by a newly found design flaw in common TCP implementations.  The flaw allows remote attackers to effectively end a TCP session by sending an RST or SYN packet with an approximated TCP sequence number and a forged source IP address.  This would reset the TCP connection and effectively cause a denial of service attack.  Microsoft is one of a long list of vendors on the affected list so you can bet the eggheads at SlashNot are going to highlight their name among them all.

Home Network Paranoia

Some have called me paranoid, but I have a slogan of “Friends don’t let friends use wireless networks.”  The reason for this is that wireless networks compromise the need for physical access to a network to perform any attack on the internal network. 

Well, I of course, do have exceptions to my wireless rule.  I’m planning on getting a new PDA with 802.11 capabilities, I’d like to be able to access the internet from it.  As such, I’ve decided go add a wireless router to my home network.  Before I did such, I wanted to make sure that my devices and laptop would only have access to the internet from the wireless network, and not to my internal network.  I don’t any stranger standing in the woods of my back yard able to access my TaxCut and MS Money files through a wireless hack, and considering the Feds can do it in 3 minutes now, I think my paranoia is justified. 

I’m not a network security guru. I used to be a network administrator, but that was over 6 years ago and hardware was much different then.  As such, I’m publishing my network layout and asking for comments or suggestions or holes that anyone might see. 


As you can see, my internet access comes in through a cable modem which connects to a VoIP-capable router (yes, I use Vonage).  The reason for using this router as my opening router is somewhat physical.  In my garage, where I terminated all of my network runs, I also terminated a cable line and phone lines at a patch panel.  Since the VoIP router also provides data ports, it’s perfect for acting as a distribution for both my planned wireless router and my 8 port routing switch.  The outgoing voice line patches into a telephone patch panel distribution that supplies the house telephone runs.  The 8 port router serves as the first layer of defense for my data network It then provides access to the whole house through the patch panel distribution point where I ran all of my data lines to. (I luckily got to do all my own structured wiring while the house was being built).

Its important to note that I do not allow access from the wireless network across the internal side of the VoIP router, and I again block packets originating from the wireless router at the 8 port.  The 8 port router and the VoIP router does, however have some rules for open ports that my wife needs to play games, and that I need for various services I have running on my internal network.  Because of this, I’ve added another Cisco PIX firewall in my upstairs office to prevent any inbound requests to my file server, my development PC, and of course the computer I use for family record keeping. The file server is behind the firewall, but I have rules set up to allow access to it from the other house PC’s.

In any case, as I look at my network, I start to realize how imperfect it is.  I’m looking for advice from anyone on how to make it more secure but still provide the needed functionality to our standard home PC’s and to our private personal-data machines.