Configuring Basic Protection Rules to Defend Against Common Web Attacks

Prerequisites

You have added your website to a policy.

Constraints

• Basic web protection has two modes: Block and Log only.
• 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 select Block for Basic Web Protection, you can configure access control criteria for a known attack source. WAF will block requests matching the configured IP address, cookie, or params for a length of time configured as part of the rule.

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 on the left, choose Policies.
5. Click the name of the target policy to go to the protection configuration page.
6. In the Basic Web Protection configuration area, change Status and Mode as needed by referring to Table 1.

   Table 1 Parameter description

   Parameter	Description
   Status	Status of Basic Web Protection : enabled. : disabled
   Mode	Block: WAF blocks and logs detected attacks. Log only: WAF only logs detected attacks.

7. In the Basic Web Protection configuration area, click Advanced Settings.
8. Click the Protection Status tab, and enable protection types one by one by referring to Table 3.
   1. Set the protective action.
      • Block: WAF blocks and logs detected attacks.

        If you select Block, you can select a known attack source rule to let WAF block requests accordingly. For details, see Configuring a Known Attack Source Rule to Block Specific Visitors for a Specified Duration.

      • Log only: WAF only logs detected attacks.
   2. Set the protection level.

      In the upper part of the page, set Protection Level to Low, Medium, or High. The default value is Medium.

      Table 2 Protection levels

      Protection Level	Description
      Low	WAF only blocks the requests with obvious attack signatures. If a large number of false alarms are reported, Low is recommended.
      Medium	The default level is Medium, which meets a majority of web protection requirements.
      High	At this level, WAF provides the finest granular protection and can intercept attacks with complex bypass features, such as Jolokia cyber attacks, common gateway interface (CGI) vulnerability detection, and Druid SQL injection attacks. To let WAF defend against more attacks but make minimum effect on normal requests, observe your workloads for a period of time first. Then, configure a global protection whitelist rule and select High.

   3. Set the protection type.
      

      By default, General Check is enabled. You can enable other protection types by referring to Table 3.

   Table 3 Protection types

   Type	Description
   General Check	Defends against attacks such as SQL injections, XSS, remote overflow vulnerabilities, file inclusions, Bash vulnerabilities, remote command execution, directory traversal, sensitive file access, and command/code injections. SQL injection attacks are mainly detected based on semantics. NOTE: If you enable General Check, WAF checks your websites based on the built-in rules.
   Webshell Detection	Protects against web shells from upload interface. NOTE: If you enable Webshell Detection, WAF detects web page Trojan horses inserted through the upload interface.
   Deep Inspection	Identifies and blocks evasion attacks, such as the ones that use homomorphic character obfuscation, command injection with deformed wildcard characters, UTF7, data URI scheme, and other techniques. NOTE: If you enable Deep Inspection, WAF detects and defends against evasion attacks in depth.
   Header Inspection	This function is disabled by default. When it is disabled, General Check will check some of the header fields, such as User-Agent, Content-type, Accept-Language, and Cookie. NOTE: If you enable this function, WAF checks all header fields in the requests.

Protection Effect

If General Check is enabled and Mode is set to Block for your domain name, to verify WAF is protecting your website (www.example.com) against general check items:

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 (Dedicated Mode).
   • If the website is accessible, go to 2.

2. Clear the browser cache and enter http://www.example.com?id=1%27%20or%201=1 in the address box of the browser to simulate an SQL injection attack.
3. Return to the WAF console. In the navigation pane, choose Events. On the displayed page, view or download events data.

Example - Blocking SQL Injection Attacks

If domain name www.example.com has been connected to WAF, perform the following steps to verify that WAF can block SQL injection attacks.

1. Enable General Check in Basic Web Protection and set the protection mode to Block.
2. Enable WAF basic web protection.
3. Clear the browser cache and enter a simulated SQL injection (for example, http://www.example.com?id=' or 1=1) in the address box.

   WAF blocks the access request. Figure 1 shows an example block page.

   Figure 1 Block page
   

4. Go to the WAF console. In the navigation pane on the left, choose Events. View the event on the Events page.