• SonicOS 7.1 Rules and Policies
• Overview
  • About SonicOS
  • SonicOS Workflow
  • How to Use the SonicOS Administration Guides
  • Guide Conventions
• Access Rules
  • Setting Firewall Access Rules
    • About Connection Limiting
    • Using Bandwidth Management with Access Rules
      • Enabling Bandwidth Management on an Access Rule
    • Creating Access Rules
    • Configuring Access Rules for IPv6
      • About Stateful Packet Inspection Default Access Rules
    • Enabling and Disabling Access Rules
    • Editing Access Rules
    • Deleting Access Rules
    • Restoring Access Rules to Default Settings
    • Displaying Access Rules
      • By Zones
      • By Column
    • Displaying Access Rule Traffic Statistics
    • Configuring Access Rules for NAT64
    • Configuring Access Rules for a Zone
    • Access Rules for DNS Proxy
    • User Priority for Access Rules
  • Access Rule Configuration Examples
    • Enabling Ping
    • Blocking LAN Access for Specific Services
    • Allowing WAN Primary IP Access from the LAN Zone
• NAT Rules
  • About NAT in SonicOS
  • About NAT Load Balancing
    • Determining the NAT LB Method to Use
    • Caveats
    • How Load Balancing Algorithms are Applied
    • Sticky IP Algorithm Examples
      • Example One - Mapping to a Network
      • Example Two - Mapping to an IP Address Range
  • About NAT64
    • Use of Pref64::/n
  • About FQDN-based NAT
  • About Source MAC Address Override
  • Viewing NAT Policy Entries
    • Changing the Display
    • Filtering the Display
    • Displaying Information about Policies
  • Adding or Editing NAT or NAT64 Rule Policies
  • Deleting NAT Policies
  • Creating NAT Rule Policies: Examples
    • Creating a One-to-One NAT Policy for Inbound Traffic
    • Creating a One-to-One NAT Policy for Outbound Traffic
    • Inbound Port Address Translation via One-to-One NAT Policy
    • Inbound Port Address Translation via WAN IP Address
    • Creating a Many-to-One NAT Policy
    • Creating a Many-to-Many NAT Policy
    • Creating a One-to-Many NAT Load Balancing Policy
    • Creating a NAT Load Balancing Policy for Two Web Servers
    • Creating a WAN-to-WAN Access Rule for a NAT64 Policy
    • DNS Doctoring
• Routing
  • About Routing
    • About Metrics and Administrative Distance
      • About Metrics
      • About Administrative Distance
    • Route Advertisement
    • ECMP Routing
    • Policy-based Routing
    • Policy-based TOS Routing
    • PBR Metric-based Priority
    • Policy-based Routing and IPv6
    • OSPF and RIP Advanced Routing Services
      • About Routing Services
        • Protocol Type
        • Maximum Hops
        • Split-Horizon
        • Poison Reverse
        • Routing Table Updates
        • Subnet Sizes Supported
        • Autonomous System Topologies
      • OSPF Terms
    • Drop Tunnel Interface
    • App-based Routing
  • Rules and Policies >
    • Configuring
      • Adding Static Routes
      • Probe-Enabled Policy-based Routing Configuration
• DNS Rules
  • Creating DNS Filtering Profiles
  • Configuring DNS Filtering
    • Creating DNS Policy Rules
      • Editing DNS Policies
      • Deleting DNS Policies
    • Configuring Global DNS Filtering Settings
    • Configuring DNS Filtering Custom Domains
  • Viewing DNS Information
    • Viewing DNS Using the Dashboard
    • Viewing DNS Filtering Reports
• Content Filter Rules
  • About Content Filtering Rules (CFS)
    • About Content Filter Rules
    • About UUIDs for CFS Policies
    • About Content Filter Action Objects
    • How CFS Works
  • Configuring CFS Policies
    • About the Content Filter Rule Table
      • Searching the Content Filter Rule Table
    • Adding a Content Filter Rule
    • Editing a Content Filter Rule
    • Deleting Content Filter Rules
• App Rules
  • About App Rules
    • What are App Rules?
      • About App Rules Policies
      • About App Rules Capabilities
    • Benefits of App Rules
    • How Does Application Control Work?
    • About App Rules Policy Creation
    • Licensing App Rules and App Control
    • Terminology
  • Rules and Policies > App Rules
    • Configuring an App Rules Policy
  • Verifying App Rules Configuration
    • Useful Tools
      • Wireshark
      • Hex Editor
  • App Rules Use Cases
    • Creating a Regular Expression in a Match Object
    • Policy-based Application Rules
    • Logging Application Signature-based Policies
    • Compliance Enforcement
    • Server Protection
    • Hosted Email Environments
    • Email Control
    • Web Browser Control
    • HTTP Post Control
    • Forbidden File Type Control
    • ActiveX Control
    • FTP Control
      • Blocking Outbound Proprietary Files Over FTP
      • Blocking Outbound UTF-8 / UTF-16 Encoded Files
      • Blocking FTP Commands
    • Bandwidth Management
    • Bypass DPI
    • Custom Signature
    • Reverse Shell Exploit Prevention
      • Generating the Network Activity
      • Capturing and Exporting the Payload to a Text File Using Wireshark
      • Creating a Match Object
      • Defining the Policy
• Endpoint Rules
• SonicWall Support
  • About This Document

HTTP Post Control

You can enhance the security of public facing read-only HTTP servers by disallowing the HTTP POST method.

To disallow the HTTP POST

1. Use Notepad or another text editor to create a new document called Post.htm that contains this HTML code:

   <FORM action="http://www.yahoo.com/" method="post">

   <p>Please enter your name: <input type="Text" name="FullName"></p>

   <input type="submit" value="Submit"> <INPUT type="reset">

2. Save the file to your desktop or a convenient location.

3. Open the Wireshark network analyzer and start a capture. For information about using Wireshark, see Wireshark.

4. In a browser, open the Post.htm file you just created.

5. Enter your name.

6. Click Submit. Stop the capture.

7. Use the Wireshark Edit > Find Packet function to search for the string POST.

   

   Wireshark jumps to the first frame that contains the requested data. You should see something like Wireshark Display. This indicates that the HTTP POST method is transmitted immediately after the TCP header information and comprises the first four bytes (504f5354) of the TCP payload (HTTP application layer). You can use that information to create a custom match object that detects the HTTP POST method.

   Wireshark Display

   

8. In SonicOS, navigate to OBJECT | Match Objects > Custom Match.

9. Click +Add.

10. Create a custom match object like this:

    

    In this particular match object you would use the Enable Settings option to create an object that matches a specific part of the payload. The Offset field specifies which byte in the payload to begin matching and helps to minimize false positives by making the match more specific. The Depth field specifies at what byte to stop matching. The Min and Max fields allow you to specify a minimum and maximum payload size.

11. Navigate to POLICY | Rules and Policies > App Rules.

12. Click +Add Rule.

13. Create a policy like this:

    

14. To test, use a browser to open the Post.htm file you created earlier.

15. Type in your name.

16. Click Submit. The connection should be dropped this time, and you should see an alert in the log similar to this one: