web-application-firewall-dedicated/umn/source/rule_configuration/configuring_a_precise_protection_rule.rst

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waf_01_0010.html

Configuring a Precise Protection Rule

WAF allows you to customize protection rules by combining HTTP headers, cookies, URLs, request parameters, and client IP addresses.

You can combine common HTTP fields, such as IP, Path, Referer, User Agent, and Params in a protection rule to let WAF allow, block, or only log the requests that match the combined conditions.

A reference table can be added to a precise protection rule. The reference table takes effect for all protected domain names.

Prerequisites

A website has been added to WAF.

Application Scenarios

Precise protection rules are used for anti-leeching and website management background protection.

Procedure

1. Log in to the management console.

2. Click in the upper left corner of the management console and select a region or project.

3. Click in the upper left corner and choose Web Application Firewall (Dedicated) under Security.

4. In the navigation pane, choose Website Settings.

5. In the Policy column of the row containing the target website, click the number to go to the policy configuration page.

6. In the Precise Protection configuration area, change Status as needed and click Customize Rule to go to the Precise Protection page.

   

   Figure 1 Precise Protection configuration area

7. On the Precise Protection page, set Detection Mode. Figure 2 <waf_01_0010__fig1818193165213> shows an example.

   Two detection modes are available:

   • Instant Detection: If a request matches a configured precise protection rule, WAF immediately ends threat detection and blocks the request.

   • Full Detection: If a request matches a configured precise protection rule, WAF finishes its scan first and then blocks all requests that match the configured precise protection rule.

     

     Figure 2 Setting Detection Mode

8. Click Add Rule.

9. In the displayed dialog box, add a rule by referring to Table 1 <waf_01_0010__table2299936310457>.

   The settings shown in Figure 3 <waf_01_0010__fig39459217174738> are used as an example. If a visitor tries to access a URL containing /admin, WAF will block the request.

   Important

   To ensure that WAF blocks only attack requests, configure Protective Action to Log only first and check whether normal requests are blocked on the Events page. If no normal requests are blocked, configure Protective Action to Block.

   

   Figure 3 Add Precise Protection Rule

   Table 1 Rule parameters

   Parameter	Description	Example Value
   Protective Action	You can select Block, Allow, or Log only. Default value: Block	Block
   Known Attack Source	If you set Protective Action to Block, you can select a blocking type for a known attack source rule. Then, WAF blocks requests matching the configured IP, Cookie, or Params for a length of time that depends on the selected blocking type.	Long-term IP address blocking
   Effective Date	Select Immediate to enable the rule immediately, or select Custom to configure when you wish the rule to be enabled.	Immediate
   Condition List	Click Add to add conditions. At least one condition needs to be added. You can add up to 30 conditions to a protection rule. If more than one condition is added, all of the conditions must be met for the rule to be applied. A condition includes the following parameters: Parameters for configuring a condition are described as follows: Field Subfield: Configure this field only when Params, Cookie, or Header is selected for Field. Important NOTICE: The length of a subfield cannot exceed 2,048 bytes. Only digits, letters, underscores (_), and hyphens (-) are allowed. Logic: Select a logical relationship from the drop-down list. Note If Include any value, Exclude any value, Equal to any value, Not equal to any value, Prefix is any value, Prefix is not any of them, Suffix is any value, or Suffix is not any of them is selected, select an existing reference table in the Content drop-down list. For details, see Adding a Reference Table <waf_01_0081>. Exclude any value, Not equal to any value, Prefix is not any of them, and Suffix is not any of them indicates, respectively, that WAF performs the protection action (block, allow, or log only) when the field in the access request does not contain, is not equal to, or the prefix or suffix is not any value set in the reference table. For example, assume that Path field is set to Exclude any value and the test reference table is selected. If test1, test2, and test3 are set in the test reference table, WAF performs the protection action when the path of the access request does not contain test1, test2, or test3. Content: Enter or select the content of condition matching. Note For more details about the configurations in general, see Table 2 <waf_01_0010__table13543174312394>.	Path Include /admin
   Priority	Rule priority. If you have added multiple rules, rules are matched by priority. The smaller the value you set, the higher the priority.	5
   Rule Description	A brief description of the rule. This parameter is optional.	None

   Table 2 Condition list configurations

   Field	Example Subfield	Logic	Example Content
   Path: Part of a URL that does not include a domain name. This value supports exact matches only. For example, if the path to be protected is /admin, Path must be set to /admin.	None	Select a logical relationship from the drop-down list.	/buy/phone/ Important NOTICE: If Path is set to /, all paths of the website are protected.
   User Agent: A user agent of the scanner to be checked.	None		Mozilla/5.0 (Windows NT 6.1)
   IP: An IP address of the visitor for the protection.	None		XXX.XXX.1.1
   Params: A request parameter.	sttl		201901150929
   Referer: A user-defined request resource. For example, if the protected path is /admin/xxx and you do not want visitors to access the page from www.test.com, set Content to http://www.test.com.	None		http://www.test.com
   Cookie: A small piece of data to identify web visitors.	name		jsessionid
   Header: A user-defined HTTP header.	Accept		text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
   Method: the user-defined request method.	None		GET, POST, PUT, DELETE, and PATCH
   Request Line: Length of a user-defined request line.	None		50
   Request: Length of a user-defined request. It includes the request header, request line, and request body.	None		None
   Protocol: the protocol of the request.	None		http

10. Click Confirm. You can then view the added precise protection rule in the protection rule list.

    

    Figure 4 Protection rules

    • To disable a rule, click Disable in the Operation column of the rule. The default Rule Status is Enabled.
    • To modify a rule, click Modify in the row containing the rule.
    • To delete a rule, click Delete in the row containing the rule.

Protection Effect

If you have configured a precise protection rule as shown in Figure 3 <waf_01_0010__fig39459217174738> for your domain name, to verify WAF is protecting your website (www.example.com) against the rule:

1. Clear the browser cache and enter the domain name in the address bar to check whether the website is accessible.
   • If the website is inaccessible, connect the website domain name to WAF by following the instructions in Step 1: Add a Website to WAF <waf_01_0250>.
   • If the website is accessible, go to Step 2 <waf_01_0010__li1160182620213>.

2. Clear the browser cache and enter http://www.example.com/admin (or any page containing /admin) in the address bar. Normally, WAF blocks the requests that meet the conditions and returns the block page.

3. Return to the WAF console. In the navigation pane, click Events. On the displayed page, view or download events data <waf_01_0077>.

Configuration Example - Blocking a Certain Type of Attack Requests

Analysis of a specific type of WordPress pingback attack shows that the User Agent field contains WordPress. See Figure 5 <waf_01_0010__fig16451834185616>.

Figure 5 WordPress pingback attack

A precise rule as shown in the figure can block this type of attack.

Figure 6 User Agent configuration