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

Vulnerable Web Applications for learning

Update: 08/08/2010: Created a tabled output of the listing. Platforms for most applications added. More applications added to list thanks to comments.

Just a quick post. Someone on the ‘NULL’ mailing asked for WebGoat alternatives to learning Web Application penetration testing. The reponse was amazing, with many applications being listed as vulnerable web applications designed for learning web-app pentest. I have collected  all vulnerable web applications and listed them below for reference:

[Tool] Unique Pattern Generator for Exploit Development

CAUTION: I have realised, that this script gives wrong results after a certain length of characters. It’s not recommended for use. The intention for this script was for me to learn some coding – which I have. But I haven’ got the time at the moment to fix the errors. Hopefully, sometime in the future, I’ll be able to re-write the code. You can use corelanc0d3r’s pvefindaddr.py, which is an excellent script for Immunity Debugger.

Update: Thanks to corelanc0d3r for pointing out that my script does not generate an output same as the metasploit and pvefindaddr scripts. This is useful, as pointed by him, to anyone wishing to mix the outputs/offsets between the tools. I have made relevant changes to the code and also fixed another bug which prevented all offsets from being calculated.

While developing exploits, at times you require a unique string for which any 4 consecutive characters selected at an instance are unique across the string(or may be repeated only after a large gap of characters). This is mostly used to find the ‘offset’ of the characters which have over-written the EIP register.

Metasploit (version 3.0+) has a tool for both:
1) to generate the string pattern (tools/pattern_create.rb)
2) to find the offset of the required pattern (tools/pattern_offset.rb)

Rediffmail XSS vulnerability disclosed

A member of the ‘NULL’ mailing-list today announced a ‘Persistent XSS’ vulnerability in the ‘subject’ parameter of RediffMail’s email application.
This Vulnerability was discovered and reported by w4rl0ck.d0wn and Rockey Killer of h4ck3r crew
Check out their PoC video at:
Rediffmail PoC

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)

Hakin9 magazine contest

Hakin9 is out with another contest. They’re giving out three latest issues of Hakin9 absolutely free.

After the last contest, I received my copy of Hakin9 in about 10 days and the issue was awesome. I can’t wait to check out the contents of the upcoming issues.

The current issue addresses advance hacking techniques like ASLR and Stack Canaries. The theme of the issue is “21st Century Hacking Techniques“

Head over to their website at http://www.hakin9.org/en to know more about the contest and the articles in the current issue.

SQL Injection in Stored Procedures

My colleague Dhiraj Ranka wrote about a very interesting topic of SQL Injections.
Though Stored Procedures provide certain protection from SQL injections, an improper implementation voids all such protections.

Dhiraj has demonstrated an SQL injection in a Stored Procedure which has not been constructed properly.

The crux of the issue lies in using the system Stored Procedure sp_executesql which takes a string as parameter and executes it. The string is generally a SQL query. So the entire premise of using stored procedures to prevent query injections fails as the input is directly inserted into the SQL query.

Read the detailed example at http://dhirajranka.wordpress.com/2009/08/25/sql-injection-stored-procedure/

Another interesting account of improper usage of Stored Procedure is demonstrated at
http://palisade.plynt.com/issues/2006Jun/injection-stored-procedures/

Regards,

Indian Honeynet Project (IHP) Launched

The official India chapter of the Honeynet Project was launched some time back.

I’ve joined in as a member as it is a very interesting project and will provide for many learning opportunities.
I’ve even submitted a report on the initial setup and analysis that we’ve done at our office. You can check it out at
http://honeynet.org.in/projects_and_reports.htm

For further details about the initiative visit http://honeynet.org.in/index.htm