Updated on 2024-04-12 GMT+08:00

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.

Prerequisites

You have added the website you want to protect to WAF.

Constraints

  • It takes several minutes for a new rule to take effect. After the rule takes effect, protection events triggered by the rule will be displayed on the Events page.
  • If you configure Protective Action to Block for a precise protection rule, you can configure a known attack source rule by referring to Configuring a Known Attack Source Rule. WAF will block requests matching the configured IP address, Cookie, or Params for a length of time configured as part of the rule.

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 under Security & Compliance.
  4. In the navigation pane on the left, choose Website Settings.
  5. In the Policy column of the row containing the domain name, click the number to go to the Policies page.
  6. In the Precise Protection configuration area, change Status as needed and click Customize Rule to go to the Precise Protection page.

  7. On the Precise Protection page, set Detection Mode.

    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.

  8. Click Add Rule.
  9. In the displayed dialog box, add a rule by referring to Table 1.

    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.

    If a visitor tries to access a URL containing /admin, WAF will block the request.

    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 IP, Params, Cookie, or Header is selected for Field.
      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.
      • 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.

    • Path Include /admin
    • User Agent Prefix is not mozilla/5.0
    • IP Equal to 192.168.2.3
    • Cookie key1 Prefix is not jsessionid

    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

    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/

    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.

    --

    XXX.XXX.1.1

    Params: A request parameter.

    • All fields
    • Any subfield
    • Custom

    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.

    --

    http://www.test.com

    Cookie: A small piece of data to identify web visitors.

    • All fields
    • Any subfield
    • Custom

    jsessionid

    Header: A user-defined HTTP header.

    • All fields
    • Any subfield
    • Custom

    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.

    • 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 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.
    • If the website is accessible, go to Step 2.

  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.

Configuration Example - Allowing a Specified IP Address to Access Your Website

You can configure two precise protection rules, one to block all requests, but then another one to allow the access from a specific IP address.