Hướng Dẫn Thực Hành - Cross Site Request Forgery combined with curl (DVWA): Lesson 10

{ Cross Site Request Forgery combined with curl }

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Section 0. Background Information

• What is Damn Vulnerable Web App (DVWA)?
  • Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is damn vulnerable.
  • Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, help web developers better understand the processes of securing web applications and aid teachers/students to teach/learn web application security in a class room environment.
• Pre-Requisite Labs
  • Damn Vulnerable Web App (DVWA): Lesson 1: How to Install DVWA in Fedora 14

• Lab Notes
  • In this lab we will do the following:
    1. We will test a basic Cross Site Request Forgery (XSRF) attack
    2. We will capture and manipulate a CSRF URL to change the admin password.
    3. We will obtain the session cookie string using a reflective XSS attack.
    4. We will create a curl CSRF string to change the admin password.

• Legal Disclaimer
   Bài lab chỉ dùng cho môi trường học tập

Section 1. Configure Fedora14 Virtual Machine Settings

1. Open Your VMware Player
   • Instructions:
     1. On Your Host Computer, Go To
     2. Start --> All Program --> VMWare --> VMWare Player
2. Edit Fedora14 Virtual Machine Settings
   • Instructions:
     1. Highlight fedora14
     2. Click Edit virtual machine settings
   • 
3. Edit Network Adapter
• Instructions:
  1. Highlight Network Adapter
  2. Select Bridged
  3. Click on the OK Button.
• 

Section 2. Login to Fedora14

1. Start Fedora14 VM Instance
   • Instructions:
     1. Start Up VMWare Player
     2. Select Fedora14
     3. Play virtual machine
   • 
2. Login to Fedora14
   • Instructions:
     1. Login: student
     2. Password: <whatever you set it to>.
   • 

Section 3. Open Console Terminal and Retrieve IP Address

1. Start a Terminal Console
   • Instructions:
     1. Applications --> Terminal
   • 
2. Switch user to root
   • Instructions:
     1. su - root
     2. <Whatever you set the root password to>
   • 
3. Get IP Address
   • Instructions:
     1. ifconfig -a
   • Notes:
     • As indicated below, my IP address is 192.168.1.106.
     • Please record your IP address.
   • 

Section 4. Temporarily Disable SELINUX and Firewall

1. Start a Terminal Console
   • Instructions:
     1. sestatus
     2. If SELinux status: is set to disabled OR if Current mode: is set to permissive, then skip the next steps, and Continue to the Next Section.
     3. If SELinux status: is set to enabled AND if Current mode: is set to enforcing, then Continue the next steps.
   • Notes:
     • In my case, I need to temporarily put selinux in permissive mode to demonstrate basic attacks on DVWA.
   • 
2. Place selinux in permissive mode
   • Instructions:
     1. echo 0 > /selinux/enforce
        • Placing a "0" in the enforce file, puts selinux in permissive mode.
     2. sestatus
        • Notice that "Current mode:" changed to permissive.
   • 
3. Disable Firewall
   • Instructions:
     1. service iptables save
        • This is not really necessary, unless you have made recent changes to the firewall.
     2. service iptables stop
        • This command disables the firewall.
   • 

Section 5. Configure BackTrack Virtual Machine Settings

1. Open Your VMware Player
   • Instructions:
     1. On Your Host Computer, Go To
     2. Start --> All Program --> VMWare --> VMWare Player
2. Edit BackTrack Virtual Machine Settings
   • Instructions:
     1. Highlight BackTrack5R1
     2. Click Edit virtual machine settings
   • 
3. Edit Network Adapter
   • Instructions:
     1. Highlight Network Adapter
     2. Select Bridged
     3. Do not Click on the OK Button.
   • 

Section 6. Login to BackTrack

1. Start BackTrack VM Instance
   • Instructions:
     1. Start Up VMWare Player
     2. Select BackTrack5R1
     3. Play virtual machine
   • 
2. Login to BackTrack
   • Instructions:
     1. Login: root
     2. Password: toor or <whatever you changed it to>.
   • 
3. Bring up the GNOME
   • Instructions:
     1. Type startx
   • 

Section 7. Open Console Terminal and Retrieve IP Address

1. Open a console terminal
   • Instructions:
     1. Click on the console terminal
   • 
2. Get IP Address
   • Instructions:
     1. ifconfig -a
   • Notes:
     • As indicated below, my IP address is 192.168.1.105.
     • Please record your IP address.
   • 

Section 8. Login to DVWA

1. Start Firefox
   • Instructions:
     1. Click on Firefox
   • 
2. Login to DVWA
   • Instructions:
     1. Start up Firefox on BackTrack
     2. Place http://192.168.1.106/dvwa/login.php in the address bar.
        • Replace 192.168.1.106 with Fedora's IP address obtained in (Section 3, Step 3).
     3. Login: admin
     4. Password: password
     5. Click on Login
   • 

Section 9. Set Security Level

1. Set DVWA Security Level
   • Instructions:
     1. Click on DVWA Security, in the left hand menu.
     2. Select "low"
     3. Click Submit
   • 

Section 10. Cross Site Request Forgery

1. CSRF Menu
   • Instructions:
     1. Select "CSRF" from the left navigation menu.
   • 
2. Basic CSRF Test
   • Instructions:
     1. New password: abc123
     2. Confirm new password: abc123
     3. Click Change
   • 
3. View Password Change Results
   • Notes:
     1. Below the change button you will notice the message that says "Password Changed."
     2. What I really want you to notice is the URL string.
     3. See how the URL string has the below two parameters separated by a "&".
        1. password_new=abc123
        2. password_conf=abc123
     4. This is DVWA's example of bad implementation of how to change a password on a web application for the following reasons:
        1. http is being used instead of https, which means this password change was in clear text.
        2. An attacker could manipulate the URL string using the address bar or curl to change the password.
     5. Continue to next step
   • 
4. Address Bar CSRF Test
   • Instructions:
     1. In the URL, after password_new=, replace abc123 with test123.
     2. In the URL, after password_conf=, replace abc123 with test123.
     3. Click the Reload Current Page Arrow
   • Notes:
     1. Notice the Password is changed
   • 
5. Copy CSRF URL
   • Instructions:
     1. Highlight the URL
     2. Right Click
     3. Copy
   • 
6. Start Notepad
   • Instructions:
     1. Applications --> Wine --> Programs --> Notepad
   • 
7. Paste URL into Notepad
   • Instructions:
     1. Edit --> Paste
   • 

Section 11. Test Password Change

1. Logout of DVWA
   • Instructions:
     1. In the Left Navigation Menu, Click Logout
   • 
2. Login to DVWA
   • Instructions:
     1. Username: admin
     2. Password: test123
   • 
3. Set DVWA Security Level
   • Instructions:
     1. Click on DVWA Security, in the left hand menu.
     2. Select "low"
     3. Click Submit
   • 

Section 12. XSS reflected

1. XSS reflected
   • Instructions:
     1. Select "XSS reflected" from the left menu navigation.
   • 
2. Submit cookie XSS attack
   • Instructions:
     1. What's your Name? <script>alert(document.cookie)</script>
     2. Click Submit
   • 
3. Copy Cookie String
   • Instructions:
     1. Highlight The Cookie String
     2. Edit --> Copy
     3. Click the OK button
   • 
4. Paste Cookie into Notepad
   • Instructions:
     1. Go back to your notepad
     2. Edit --> Paste
   • 

Section 13. Build Curl String

1. Open a console terminal
   • Instructions:
     1. Go to notepad
     2. In notepad type the following
        1. curl --cookie "" --location ""
        2. Place the cookie string between the quotes after the --cookie tag.
        3. Place the html string between the quotes after the --location tag.
     3. Your string should now look like the below line and picture
        1. curl --cookie "security=low; PHPSESSID=3juclcme0enmmhns9t36mi4ij0" --location "http://192.168.1.106/dvwa/vulnerabilities/csrf/?password_new=test123&password_conf=test123&Change=Change#"
     4. Replace the "test123" password with "password"
        1. curl --cookie "security=low; PHPSESSID=3juclcme0enmmhns9t36mi4ij0" --location "http://192.168.1.106/dvwa/vulnerabilities/csrf/?password_new=password&password_conf=password&Change=Change#"
   • 
2. Copy Curl String
   • Instructions:
     1. Highlight Curl String
     2. Edit --> Copy
   • 
3. Open a console terminal
   • Instructions:
     1. Click on the console terminal
   • 
4. Execute Curl String
   • Instructions:
     1. cd /root
     2. Edit --> Paste
     3. Append the following to your curl string
        • | grep "Password Changed" | tee curl.txt
     4. Press <Enter>
   • 
5. Verify Curl Results
   • Notes:
     1. Your should see the Password Changed message you saw earlier, when you changed your password using the CSRF menu.
   • 

Section 14. Test Curl String Password Change

1. Logout of DVWA
   • Instructions:
     1. In the Left Navigation Menu, Click Logout
   • 
2. Login to DVWA
   • Instructions:
     1. Username: admin
     2. Password: password
   • 
3. Welcome to DVWA
   • Notes:
     1. If you see the Welcome Screen, then you have successful use curl to change the password remotely without a browser.
   • 

Section 15. Proof of Lab

1. Proof of Lab
   • Proof of Lab Instructions:
     1. Pull up a BackTrack Terminal Window
     2. cd /root
     3. ls -l | grep curl.txt
     4. grep -i "password change" curl.txt
     5. date
     6. echo "Your Name"
        • Replace the string "Your Name" with your actual name.
        • e.g., echo "John Gray"
     7. Do a <PrtScn>
     8. Paste into a word document
     9. Upload to Website AnToanThongTin.Edu.Vn
   •