User manual SONICWALL SONICOS 5.8 APPLICATION FIREWALL FEATURE MODULE REV A

[. . . ] Application Control / Application Firewall in SonicOS Enhanced 5. 8 Document Scope This document describes how to configure and manage the Application Control and Application Firewall features in SonicOS 5. 8. This document contains the following sections: · · · · · · "Application Control / Application Firewall Overview" on page 1 "Licensing Application Control / Application Firewall" on page 25 "Using Application Firewall and Application Control" on page 26 "Useful Tools" on page 45 "Use Cases" on page 52 "Glossary" on page 80 Application Control / Application Firewall Overview This section provides an introduction to the SonicOS 5. 8 Application Control and Application Firewall features. This section contains the following subsections: · · · · · "What are Application Control and Application Firewall?" on page 1 "Benefits" on page 3 "How Do Application Control and Application Firewall Work?" on page 4 "Supported Platforms" on page 24 "Supported Standards" on page 25 What are Application Control and Application Firewall? In SonicOS 5. 8, the Application Firewall feature of previous SonicOS releases has been significantly enhanced with Application Control functionality. As part of this solution, the set of application relevant signatures have been extracted from the existing set of IPS signatures and placed under the realm of the Application Control feature. [. . . ] Step 15 Click OK. Using the Application Firewall Wizard The Application Firewall wizard provides safe configuration for many common use cases, but not for everything. If at any time during the wizard you are unable to find the options that you need, you can click Cancel and proceed using manual configuration. To use the wizard to configure Application Firewall, perform the following steps: Step 1 Step 2 Step 3 Step 4 Step 5 Login to the SonicWALL security appliance. In the SonicWALL banner at the top of the screen, click the Wizards icon. Select the Application Firewall Wizard radio button and then click Next. In the Application Firewall Policy Type screen, click a selection for the policy type, and then click Next. You can choose among SMTP, incoming POP3, Web Access, or FTP file transfer. The policy that you create will only apply to the type of traffic that you select. The next screen will vary depending on your choice here. Application Control and Application Firewall 21 Using Application Control Step 6 In the Select <your choice> Rules for Application Firewall screen, select a policy rule from the choices supplied, and then click Next. Depending on your choice in the previous step, this screen is one of four possible screens: · · · · Select SMTP Rules for Application Firewall Select POP3 Rules for Application Firewall Select Web Access Rules for Application Firewall Select FTP Rules for Application Firewall Step 7 The screen displayed here will vary depending on your choice of policy rule in the previous step. For the following policy rules, the wizard displays the Set Application Firewall Object Keywords and Policy Direction screen on which you can select the traffic direction to scan, and the content or keywords to match. · · · · All SMTP policy rule types except Specify maximum email size All POP3 policy rule types All Web Access policy rule types except Look for usage of certain web browsers and Look for usage of any web browser, except the ones specified All FTP policy types except Make all FTP access read-only and Disallow usage of SITE command In the Set Application Firewall Object Keywords and Policy Direction screen, perform the following steps: · · In the Direction drop-down list, select the traffic direction to scan from the drop-down list. Do one of the following: Note If you selected a choice with the words except the ones specified in the previous step, content that you enter here will be the only content that does not cause the action to occur. See "Negative Matching" on page 14. ­ In the Content text box, type or paste a text or hexadecimal representation of the content to match, and then click Add. Repeat until all content is added to the List text box. ­ To import keywords from a predefined text file that contains a list of content values, one per line, click Load From File. · Click Next. If you selected a policy type in the previous step that did not result in the Set Application Firewall Object Keywords and Policy Direction screen with the standard options, the wizard displays a screen that allows you to select the traffic direction, and certain other choices depending on the policy type. · · · In the Direction drop-down list, select the traffic direction to scan. SMTP: In the Set Maximum Email Size screen, in the Maximum Email Size text box, enter the maximum number of bytes for an email message. Web Access: In the Application Firewall Object Settings screen, the Content text box has a drop-down list with a limited number of choices, and no Load From File button is available. FTP: In the special-case Set Application Firewall Object Keywords and Policy Direction screen, you can only select the traffic direction to scan. Click Next. · · 22 Application Control and Application Firewall in SonicOS 5. 8 Using Application Control Step 8 In the Application Firewall Action Settings screen, select the action to take when matching content is found in the specified type of network traffic, and then click Next. You will see one or more of the following choices depending on the policy type, as shown below: Policy Type All Types All Types SMTP SMTP SMTP POP3 Web Access Web Access Web Access Web Access Available Action Log Only Bypass DPI Blocking Action - block and send custom email reply Blocking Action - block without sending email reply Add Email Banner (append text at the end of email) Blocking Action - disable attachment and add custom text Blocking Action - custom block page Blocking Action - redirect to new location Blocking Action - Reset Connection Manage Bandwidth Step 9 In the second Application Firewall Action Settings screen (if it is displayed), in the Content text box, type the text or URL that you want to use, and then click Next. The second Application Firewall Action Settings screen is only displayed when you selected an action in the previous step that requires additional text. For a Web Access policy type, if you selected an action that redirects the user, you can type the new URL into the Content text box. Step 10 In the Select Name for Application Firewall Policy screen, in the Policy Name text box, type a descriptive name for the policy, and then click Next. Step 11 In the Confirm Policy Settings screen, review the displayed values for the new policy and do one of the following: · · · To create a policy using the displayed configuration values, click Apply. To exit the wizard without creating the policy, click Cancel. Step 12 In the Application Firewall Policy Complete screen, to exit the wizard, click Close. Note You can configure Application Firewall policies without using the wizard. [. . . ] In the Content text box, type the bytes as shown by Wireshark: 474554. In the Application Firewall Policy Settings window (Figure 57), type a descriptive policy name and select HTTP Client for the policy type. In the Match Object drop-down list, select the match object that you just defined. For more information about creating a policy, see "Configuring an Application Firewall Policy" on page 43. Application Control and Application Firewall 21 Using Application Control The policy settings are shown below. Figure 57 HTTP GET Blocking Policy 22 Application Control and Application Firewall in SonicOS 5. 8 Using Application Control Reverse Shell Exploit Prevention The reverse shell exploit is an attack that you can prevent by using Application Firewall's custom signature capability (See "Custom Signature" on page 74). [. . . ]