People often overlook printers when it comes to information security. Truth is that a ton of useful information can be found in printers. Employees will often scan sensitive documents such as social security cards, loan information, birth certificates, etc. I’ve also seen important organizational information on printers such as internal memos between higher up executives. The documents I’ve seen in the past were never meant to be shared but a default printer will more than happily share your sensitive information. Almost any new commercial printer will come with a ton of features to store and retrieve any documentation that flows through the printer (copy, scan, and print jobs). Almost all of these new printers also give you a web interface to retrieve that documentation, an example of a printer’s web interface can be seen here. When I’m performing a penetration test I always go for the web interface of a printer, the web interface is where I can grab all the sensitive information. These printers usually get unboxed and plugged into the network without much configuration from the default state, this means that the web interface is wide open with default usernames and passwords. Usually admin access to these printers will give you more access and it’s this admin access that I check for.

When you’ve only got a limited amount of time during a penetration test you want to get the best bang for your buck so I created a python script that will go and check for default usernames and passwords on certain models of printers. Below is the python script.

Usage:  at the command line type the following

So this script takes two arguments, 1) A list of IP’s you’ll want to test against, 2) Name of an output file where successful attempts are logged. If you’re having troubles running the script read my other post about running a python script. The output.txt will contain a list of IP’s that the script was able to log into. There are three variables that you’ll have to modify for your particular printer model that you are trying to scan for on your network, they are listed below.

Username and password variables should be obvious, simply put in the default username and password of the printer on your network. The only thing you’ll have to change in ‘theurl’ variable is the last quoted string. In my case it was ‘/index.html’, in your case it could be ‘/auth/login.html’. Variable ‘theurl’ builds the http request used to log into your printer’s web interface. A full example is below.

This script is doing nothing more than trying to log into the web interface of a printer, that’s it. So the script is not limited to printers, it can be used against any web application that takes a username and password. Although this script can be used against any web application there is a limitation.  This script authenticates to the printer using Basic Access Authentication. There are three main ways to authenticate to a web application.

1. HTTP Basic Access Authentication
2. HTTP Digest Access Authentication
3. HTML Form-based Authentication

So this script will not work if your web application (printer in this case) is using the second or third option. How would you know which one your printer or web application is using? Turns out OWASP has a nice write up on how to test which type of authentication your web application is using. Turns out that no one really uses one and two because they are not as secure as HTML Form-based Authentication wrapped inside SSL. Of course some printers use Basic Authentication because they are poorly built. Basic Authentication actually passes your username and password essentially in plaintext, the only way it tries to hide your username and password is by base64 encoding them which is easily transformed back into plaintext. I don’t want to get lost in the weeds to much but just knowing that your printer is using Basic Authentication is bad enough. Even if you set a strong username and password anyone sniffing network traffic would be able to determine your credentials.

I kicked this script over to Dave Huggins who has tons of experience developing Python applications and he quickly improved upon it by adding the functionality of IP ranges instead of a file. His enhancements can be seen below.

Happy printer hunting.

Part 2 covered the neat functionality of session ID analysis within Webscarab. Now we’ll focus on another great function within Webscarab, fuzzing. I define fuzzing as testing the input of an application by trying various parameters that the input may not expect. These parameters don’t have to be random, in my opinion it’s best when you tailor your parameters depending on the application. When fuzzing you typically want to inject “command & control” parameters into the input to find the most serious vulnerability. For example if a web application is expecting a social security number I may inject html parameters such as ” < / > ” to manipulate the look, feel, and operation of a web application. I don’t want to delve a whole lot into fuzzing because there are books out there that talk about this one subject. This tutorial is going to focus on using Webscarab to fuzz web applications and find vulnerabilities. Hopefully by the end of this tutorial you will better understand the technical aspects of fuzzing as oppose to the concept of fuzzing, but more reading on fuzzing web applications may be required.

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Part 1 of this series focused on the basics of using a HTTP proxy to assess a web application. I encourage people to play around with HTTP proxies with a web application that they use frequently, it’s interesting to see what information is being passed between the client and server. This communication can sometimes include your private information so it’s good to understand how that particular web application is handling your information.

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This tutorial is designed to walk you through the basics of using a HTTP proxy. A HTTP proxy is very useful when it comes to web application vulnerability assessment. A proxy will allow you to record all of your transactions while using the web application producing a history of pages you have visited and links you have clicked. A proxy also allows you to see the HTTP request and responses, basically you’ll see what is being sent behind the scenes. This document will go into more detail about what a HTTP proxy can do as we step through some exercises on analyzing traffic from a web application.

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The purpose of this tutorial is to give a quick, concise overview of how to secure your communications through a non-trusted or insecure channel. You could also use this tutorial to evade organizational firewalls and web filters but, I am more concerned about keeping my communications private rather than evading organizational filters. I have seen other tutorials that show how to accomplish tunneling http traffic over SSH but not in a very simple manner, so I hope this tutorial will accomplish this goal as well as help others. As always your feedback is welcome, either by commenting on this article or via my contact form.

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