Transcript Damn Vulnerable web application

Sara Sartoli
Akbar Siami Namin
NSF-SFS workshop
July 14-18, 2014
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How to install and run DVWA
Exploit a some SQL Injection attacks
Upload a malicious file
Exploit an XSS attack
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DVWA is a PHP/MySQL web application that is damn
vulnerable to most common web attacks.
The main goals are:
◦ to be an aid for security professionals to test their skills and
tools in a legal environment.
◦ to help web developers better understand the processes of
securing web applications.
◦ To be an for aid teachers/students to teach/learn web
application security in a class room environment.
1.
Install Xampp
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Download DVWA and extract that
Copy DVWA folder in web server root
Go to DVWA Directory>>Config>> Open config.inc.php and
change $_DVWA[ 'db_password' ] = 'p@ssw0rd' to $_DVWA[
'db_password' ] = 'p@ssw0rd' to $_DVWA[ 'db_password' ] =''
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A SQL injection attack consists of insertion or “injection” of a
SQL query via the input data from the client to the application.
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In SQL injection, SQL commands are injected into data-plane
input in order to effect the execution of predefined SQL
commands.
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Input data must be validated to ensure that the web application
is operated on clean, correct and useful data .
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The query, executed back in the database looks like:
SELECT first_name, Last_Name from users where ID=‘1’;
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A solution that would extract all the first name and passwords
from the table is to use following injection string:
SELECT first_name, Last_Name from users where ID=‘1’ or ‘0’=‘0’;
The basic idea is to make the database to respond with error message
containing database type and version.
 Entering a quote make the DB to consider any characters after quote as a
simple string and non sql code and cause syntax error.
 Now we know that the database is MySQL so we can use appropriate
queries to find out the version.
 In MySQL the queries that return the version are:
SELECT version()
SELECT @@version
 Enter the following srings:
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‘ union select @@version#
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' union select null, @@version #
 The query that would extract DB version is:
SELECT first_name, Last_Name from users where ID=‘ ’union select null,
@@version #’;
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In MySQL the queries that retrieve the host_name anddatabase
name are:
SELECT database()
SELECT @@ hostname()
So, What would be the injection string????
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Information schema is a database that contains information about
all of databases that the installed MySQL contains.
Enter the following string:
a' UNION select table_schema,table_name FROM
information_Schema.tables;#
Try to find damn vulnerable web app database and its tables.
Now , set DVWA to high security and attack again.
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The first step in many attacks is to get some code to
the system to be attacked. Then the attacker only
needs to find a way to get the code executed. Using a
file upload helps the attacker accomplish the first step.
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Copy a JPG file and a PNG file to the root.
Choose a PHP file in the root Path and try to upload that.
Try to upload JPG and PNG file as well.
Give it a try with medium and high security.
Note:
 Check the PHP code to figure out What the differences are?
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Cross-Site Scripting attacks are a type of injection
problem, in which client-side script is injected into
web pages viewed by other users.
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Select “XSS Stored” from the left navigation menu.
Name: Test 1
Message: <script>alert(“my xss attack”)</script>
Sign guestBook
Note:
 This XSS exploit will be displayed for all of users.
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Reset the DataBase
Select “XSS Stored” from the left navigation menu.
Input Name: Test 2
Input Message: <iframe src=“http://www.cnn.com”></iframe>
Sign Guest Book
Notes:
 We need to reset the database otherwise the each XSS exploit will
appear for each example.
 This is a powerful exploit because a user could use SET to create
Malicious cloned website and place in here.
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Reset the DataBase
Select “XSS Stored” from the left navigation menu.
Input Name: Test 3
Input Message: <script>alert(document.cookie)</script>
Sign Guest Book
Notes:
 It is possible to modify this XSS script to send the cookie to a
remote location instead of displaying it.(man in the middle attack)
 Check the PHP code to figure out What the differences are?
Thank you