Hacking Guest Wifi Networks

(Cross-posting from my organization’s blog – http://niiconsulting.com/checkmate/2014/03/insecure-implementation-guest-wireless-networks/)

Most large organizations provide wireless facilities for their guest, which may include vendors, consultants, business associates, employees from other regions etc.

Certain points should be considered while implementing a guest wireless network.

  1. Encryption in use
  2. Captive Portals or Guest Authentication
  3. Network Segregation

Finding the SSID of a Hidden wireless network

To simplify the connectivity for guest devices some organizations configure their networks without encryption i.e. ‘OPEN’. To prevent un-authorized entities from connecting to their networks most of these networks are configured as HIDDEN. As is well known, this configuration does not really provide any security. It is simply a method of obfuscation (Non-Broadcast Wireless SSIDs Why hidden wireless networks are a bad idea).

To identify the SSID of a hidden network you would need:

  1. Wireless adapter which supports packet injection (http://www.aircrack-ng.org/doku.php?id=compatible_cards)
  2. Aircrack-ng wireless suite (http://www.aircrack-ng.org/)

I will be using an Alfa AWUS036H adapter. This card is well supported by Aircrack-ng.

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How-to: Modify Apache-Coyote/1.1 Banner

If you’ve ever done a penetration test or got one done, you may have come across the following scenario:

HTTP Service running on port 8080, revealing the version information of the product in it banner.
The banner  revealed is Apache-Coyote/1.1.
This is the banner of the Apache Tomcat Web Server which runs on port 8080 by default.

Apache-Coyote/1.1 Version Disclosure

Now, as per good security practice, the banner should be removed or modified, so that it no longer reveals the version number.
This can be achieved by editing your server.xml configuration file found at the below location:

CATALINA_HOME/conf/server.xml

Original server.xml reveals version information

Modified server.xml

You may need to restart your server for the changes to reflect.
Once the Tomcat server is up, test the server to see if it shows the custom header.

 

> telnet localhost 8080
HEAD / HTTP/1.0
<CRLF>
<CRLF>

Web Server with Custom HTTP Banner

 

Hope this helps others who are looking for a solution to the banner version disclosure

Check out OWASP’s article on Securing Tomcat for more details.

Wasim

Windows (Trusted) Authentication Vs SQL (Mixed-Mode) Authentication

Just a quick post for my future reference on the differences between Trusted authentication and Mixed-mode Authentication used by SQL Server

Windows Authentication

  • When a user connects through a Windows user account, SQL Server validates the account name and password using the Windows principal token in the operating system. This means that the user identity is confirmed by Windows.
  • SQL Server does not ask for the password, and does not perform the identity validation.
  • Windows Authentication is the default authentication mode, and is much more secure than SQL Server Authentication.
  • Windows Authentication
    • uses Kerberos security protocol,
    • provides password policy enforcement with regard to complexity validation for strong passwords,
    • provides support for account lockout,
    • and supports password expiration.
  • A connection made using Windows Authentication is sometimes called a trusted connection, because SQL Server trusts the credentials provided by Windows.

SQL Authentication

  • When using SQL Server Authentication, logins are created in SQL Server that are not based on Windows user accounts.
  • Both the user name and the password are created by using SQL Server and stored in SQL Server.
  • Users connecting using SQL Server Authentication must provide their credentials (login and password) every time that they connect.
  • When using SQL Server Authentication, you must set strong passwords for all SQL Server accounts.
  • Three optional password policies are available for SQL Server logins.
    • User must change password at next login
    • Enforce password expiration
    • Enforce password policy
  • SQL Server Authentication cannot use Kerberos security protocol.
  • Supports environments with mixed operating systems, where all users are not authenticated by a Windows domain.

Source: http://msdn.microsoft.com/en-us/library/ms144284.aspx

Exploiting ActiveX

I’ve been reading a very interesting paper over the weekend. It’s about exploiting ActiveX controls implemented in the Microsoft Windows OS (mostly IE).
The article is very lucid and easy to understand even for beginners. The paper is titled “ActiveX – Active Exploitation” and it’s written by ‘warlord’

Highly recommended. You can find the article here. I’m also adding it to my Reading Room for future reference.

Deobfuscating Javascript Malware

An edited version of this post has been added to my company blog at Checkmate

Some days back I was greeted by a Google Safe browsing warning when I tried visiting a ‘known’ site. As I was sure it was supposed to be clean and harmless site, I thought it would be good to dig further into this problem. The trail led to interesting amounts of codes, concepts and techniques.

Malware writers are very smart nowadays (haven’t they always been ?). They know that once their code is understood it most likely to be detected by anti-malware applications. To delay detection by such applications, they resort to a wide range of techniques. In this blog post I’ll be discussing the most potent and easily created malware.

Javascript has become the boon and bane of the Internet. It provides greater interactivity with the user but can also be used by malware writers to infect innocent users. Javascript is a client-side scripting technology which means the processing of the script is handled by the user’s browser.

Obfuscation is the concealment of intended meaning in communication, making communication confusing, intentionally ambiguous, and more difficult to interpret.

JavaScript is sometimes obfuscated to prevent users from easily understanding their functionality. ( Legitimate uses are to prevent stealing of code)
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