This partnership was possible because of our constant search for excellence, our customer need driven approach to consulting and our service quality. More deals like this, and Bonsai will be soon named Oak!

“An open redirect is an application that takes a parameter and redirects a user to the parameter value without any validation. This vulnerability is used in phishing attacks to get users to visit malicious sites without realizing it.”

The following Proof of Concept was sent to the Twitter security team:

https://twitter.com/login?redirect_after_login=http://www.bonsai-sec.com

After a successful login, the affected user is redirected to http://www.bonsai-sec.com without any warning allowing possible phishing attacks.

This vulnerability was patched by Twitter security team last week (after we reported it and got almost no answer from them).

Detailed information can be found at: http://www.bonsai-sec.com/en/research/vulnerabilities/twitter-open-redirect-0108.php

Bonsai Information Security participó siendo Sponsor y presentando a Nahuel Grisolía, Project Leader de Bonsai, como ponente en una de las charlas.

Más información sobre el OWASP Day aquí.

A continuación, las Slides que se utilizaron en el evento:

El training de Web Application Security de Bonsai se focaliza en el descubrimiento y explotación, manual y automático, de vulnerabilidades en aplicaciones Web. Durante este curso de dos dias, se presentarán una serie de temas teóricos seguidos de prácticas hands-on realizadas por los asistentes. En cada práctica encontrarás vulnerabilidades para explotar, cada una con un diferente nivel de complejidad, las que desafiarán tu comprensión del tema.

Fechas, Ubicación, Cupos y Beneficios

• Consta de dos días completos de 9 a 18 horas. Los días asignados para el próximo training son el Martes  27 y Miércoles 28 de Julio de 2010.
• Se realizará en las aulas multimediales de IT Training Center, Sarmiento 1113, Ciudad Autónoma de Buenos Aires, Capital Federal.
• Al mediodia, los asistentes poseen el beneficio de almorzar en Il’Gato sin cargo.
• Consultar aquellos que deseen un Estacionamiento con precio preferencial.
• Capacidad: 16 asistentes

Más Información

Let’s focus on Cacti and use it as our case study as we’ve recently found its latest vulnerabilities using this technique. The next steps were followed to identify and exploit the latest Cacti OS commanding vulnerability found by our research team:

1. Download Cacti 0.8.7e
2. Uncompress Cacti
3. Under Cacti’s directory, find Operating System Function calls, such as “system”, “exec”, “shell_exec” or “popen”

1. $ grep –i –r “shell_exec(” *

1. The above command should result in some scripts using shell_exec PHP function
2. Edit one of those, for example, “lib/ping.php” and take a deeper look at it, near the OS call.
3. The function “ping_icmp” in “Net_Ping” class is using shell_exec function without sanitizing the host parameter. Uhmm… interesting!
4. Let’s see, where ping_icmp function is being called and let’s find out if we can manipulate hostname parameter in order to do our injection.
5. Note that in lib/ping.php, line 634, ping_icmp is being used inside the “ping” function.
6. Let’s search where Net_Ping is being used and where the ping function is being called and have a real look at the host parameter.
7. $ grep –i –r “net_ping” *
8. Ok! host.php script is using Net_Ping class, let’s have a deeper look again…
9. Line 625 in host.php script: note that the hostname is being used as a parameter, again, without sanitizing it.

1. So, if inside the application, you create a device (or host) with FQDN (without single quotes) ‘NotARealIPAddress;CMD;’, save it, and then, reload any data query, CMD will be executed with Web Server rights. More information on this, can be found in OS Commanding Injection in Cacti.

1. Eureka! 0day vulnerability found!

This is just an example of how some vulnerabilities might be identified and exploited using simple but effective techniques in real world applications.

You can also find other techniques to identify Web Application vulnerabilities, such as using Google’s code search.  Consider revising this article and this blog post too.

En el contexto del séptimo Congreso Internacional de Seguridad de la Información, Andrés Riancho recibió el premio Segurinfo 2009 por sus esfuerzos en el desarrollo del software de detección de vulnerabilidades Web Open Source, w3af. Queremos felicitarlo y al resto de los desarrolladores del proyecto por un muy merecido premio.

The general consensus of course was “very easy”. The problem was that we were unable to find any good CAPTCHA breaking software that average joe could download and run on his computer; so I spent some minutes creating a simple Python script that returns the CAPTCHA solution for this particular implementation.

Before we dig into the script, lets analyze why this CAPTCHA is weak (might not be obvious for some readers):

1. The letters are not rotated
2. All letters have the same height
3. All letters have the exact same color
4. The letters are not deformed in any way
5. The background noise color is the same for the whole image

Now, lets see the code that breaks this CAPTCHA:

from PIL import Image

img = Image.open('input.gif')
img = img.convert("RGBA")

pixdata = img.load()

# Clean the background noise, if color != black, then set to white.
for y in xrange(img.size[1]):
    for x in xrange(img.size[0]):
        if pixdata[x, y] != (0, 0, 0, 255):
            pixdata[x, y] = (255, 255, 255, 255)

img.save("input-black.gif", "GIF")

#   Make the image bigger (needed for OCR)
im_orig = Image.open('input-black.gif')
big = im_orig.resize((116, 56), Image.NEAREST)

ext = ".tif"
big.save("input-NEAREST" + ext)

#   Perform OCR using pytesser library
from pytesser import *
image = Image.open('input-NEAREST.tif')
print image_to_string(image)

This simple script works with ~ 90% of the CAPTCHA images created using this specific implementation. Enjoy!

The w3af ninja training course is focused on manual and automated discovery and exploitation of web application vulnerabilities using w3af. During this course you’ll also learn how to write your own exploits and customized plugins in order to achieve your goals during a web application penetration test.

This course is an intense hands-on class in which you won’t stop learning for a minute. In each practice we’ll focus on a particular type of web application vulnerability which will be analyzed and understood manually and then it’s detection and exploitation is automated using w3af.

All around the training interesting plugin code snippets will be subject to analysis and modification, which will give you great understanding of the framework and will also give you the means to automate your future web application penetration tests.

Important information

• Date: December 17th / 18th 2009
• Training partners: NopSec, Inc. SOC – 155 Water St., Brooklyn, NY 11201 USA
• More information, and registration is available here.

This is a great opportunity to master the w3af framework, don’t miss it!

The vulnerability that we’re going to be exploiting is a persistent cross site scripting in Achievo . For those that do not know, Achievo is a flexible web-based resource management tool for business environments. Achievo’s resource management capabilities will enable organizations to support their business processes in a simple, but effective manner. This vulnerability was found a while ago by our research team, and has been fixed in version 1.4.0.

The vulnerability is a really basic persistent XSS, where we can write virtually anything in the title of a scheduled meeting. As the meetings from a user can be seen by other users, and most interestingly administrators, the XSS can be exploited to elevate privileges in the application.

With the objective of writing the XSS payload, I developed a JavaScript export feature, that allows w3af users to export any HTTP request to JavaScript, that will reproduce the same request when a user loads the script in a browser.

Using the newly created feature, we were able to easily create a JavaScript payload, that when accessed by an Achievo administrator will perform the following tasks:

• Create a new application profile
• Apply administrator privileges to the profile
• Assign the newly created profile to a common user

You can find the customized XSS payload by clicking here. In order to exploit this vulnerability, a user would need to change the first four variables in the script, upload the script to a publicly accessible web server, and then point the Cross Site Scripting to that resource. After some time, and if an Achievo administrator browses through the schedule, the configured user will elevate their privileges to administrator.

In this case it was impossible (because of the application not having that particular feature) to actually upload new files to the web server, but in many other Web applications, it would have been completely possible to create a XSS payload that would use the administrator privileges to upload a specially crafted file to the web server, which would then provide operating system access to the intruder.

With the creation of tools like w3af’s JavaScript export feature, and the huge amount of XSS vulnerabilities found every day, we think that the time for customized XSS payloads written in minutes instead of hours, has arrived!

Here is some extra information regarding the training,

Training name: Discovery and exploitation of web application vulnerabilities

Overview

This training course focus is on manual and automated, discovery and exploitation of web application vulnerabilities. During this course you are going to go through a series of lectures followed by hands on practice. In each practice you will find vulnerabilities to exploit, each with a different level of complexity, which will defy your understanding of the subject. After the hands on practice, a small lecture on how the vulnerability is fixed is presented, together with common errors introduced by developers in that process.

The training will also teach you how to use the most advanced tools used by professionals in the field, like w3af (developed by the trainer), the burp suite, sqlmap and many others.

Course Structure

This is a two-day course that combines lectures with increasingly difficult hands-on exercises designed to teach the attendee different ways to discover and exploit web application vulnerabilities. All course materials, and a certificate of completion will be offered. You must provide your own laptop.

Deliverables

- Training booklet with printed slides and trainer comments
- Live CD with Web Application Security Tools
- VMware image with the training environment
- w3af T-Shirt ;)

Audience

Security consultants, system and network administrators, experienced web application developers, information security officers, government agencies.

Topics Covered

• Day One
  1. HTTP protocol review
     • Web architecture
     • HTTP headers and methods
     • HTTP authentication
     • HTTPS
     • Session management: cookies
  2. Common web server misconfigurations
     • Banners
     • Directory Indexing
     • HTTP authentication
     • HTTP method restrictions
  3. Common development and configuration errors
     • HTML comments and versioning
     • File inclusions
     • Backup and local database files
     • Hidden HTML Fields
     • Path Disclosure and directory enumeration
     • Exceptions and error messages
  4. Types of analysis
     • Static code analysis, black box testing and gray box testing:
     • Definitions
     • Vulnerabilities that can be detected
     • Vulnerabilities that CAN’T be detected
  5. Web Application Vulnerabilities
     • Reverse engineering of Java applets y Flash movies
     • Local file read
     • Local file inclusions
     • Path Traversal and Null Bytes
     • Remote file inclusions
     • Cross Site Scripting (XSS)
     • Cross Site Tracing
     • Cross Site Request Forgeries / Session Riding
     • HTTP Response Splitting
• Day Two
  1. Web Application Vulnerabilities
     • Uncommon attack vectors
     • LDAP Injection
     • OS Commanding
     • SQL Injection:
       • Enumeration of tables and columns
       • Execution of queries and stored procedures
       • Creation of files
       • Execution of OS commands
     • Blind SQL Injection
  2. Web application privilege escalation
     • Session handling
     • Logical vulnerabilities
  3. Countermeasures
     • mod_security
     • Hardening for Java
       • HDIV
       • Spring Security
     • PHP hardening:
       • Secure configuration parameters
       • GRASP
       • PHP-IDS