Strengthening IIS security requires five steps: 1. Disable unnecessary functions and services, such as WebDAV, FTP, etc.; 2. Close the default website and test pages, delete or prohibit access to useless script directories; 3. Configure request filtering rules to prevent illegal extensions, directory traversal and super long URLs, and use URLs to rewrite and hide the real path; 4. Enable HTTPS and force jumps, and set security response headers such as HSTS, X-Content-Type-Options; 5. Regularly update system patches, enable logging and use tools to analyze abnormal access behavior. Through these measures, we can effectively prevent common attack methods such as SQL injection, XSS, directory traversal, and improve the overall security of the server.

Website security is not a big deal, but it will be troublesome if there is a problem. IIS (Internet Information Services) is a commonly used Web server software on Windows platforms. If you do not protect it well, it is easy to become a target of attack. Common vulnerabilities such as SQL injection, XSS, and directory traversal. Once exploited, data leakage may occur at the least, and servers may fall. Therefore, it is necessary to configure the security settings of IIS.

Below are some key points that can help you effectively strengthen IIS and prevent common vulnerabilities from being exploited.

Disable unnecessary features and services

When installing IIS by default, some functional modules that you cannot use at all may be enabled, such as WebDAV, FTP service, CGI support, etc. If these functions are not useful and still turned on, they will increase the attack surface.

• Check Server Manager or use PowerShell command to uninstall unused roles and features
• Close the default website and test pages to avoid exposure to sensitive information
• If ASP.NET is not required, do not install related components

For example, many attackers will try to access old script files in the /scripts directory. If you don't use these at all, deleting or banning access is the most convenient way.

Configure request filtering and URL rewrite rules

The request filtering module (Request Filtering) that comes with IIS can help you block some malicious requests, such as paths containing special characters, excessively long URLs, illegal extensions, etc.

You can add the following types of filtering rules:

• Reject extension requests that are not supported by the current environment, such as .php and .asp (especially in pure static sites)
• Block paths containing ../ to prevent directory traversal attacks
• Limit URL length to prevent buffer overflow attacks

In addition, combined with the URL rewrite module (URL Rewrite), the real path structure can be hidden, such as turning /user?id=123 into /user/123 , which is both beautiful and reduces the risk of parameter injection.

Enable HTTPS and configure security response headers

It is too dangerous to transmit data in HTTP plaintext, and now basically all websites should enable HTTPS. In addition to applying for a certificate, there are several other things to note:

• Forced HTTPS jump, which can be implemented through IIS's URL rewrite rules.
• Use HSTS (HTTP Strict Transport Security) response header to tell the browser that you can only access your website via HTTPS in the future
• Add security headers such as X-Content-Type-Options, X-Frame-Options, Content-Security-Policy to prevent MIME type sniffing, click hijacking, cross-site scripting and other problems

These response headers can be configured in the IIS web.config file or can be set through the IIS management interface.

Regular updates and log monitoring should not be missing

Many people ignore it after installing IIS. In fact, system patches and updates to IIS themselves are very important. Microsoft often fixes various vulnerabilities, and not updating it in time is equivalent to leaving a backdoor.

In addition, log monitoring cannot be ignored. suggestion:

• Turn on IIS logging and archive regularly
• Set up log analysis tools (such as ELK, Splunk, or simple LogParser) to identify exception access modes
• Monitor frequent 404 errors, surge in POST requests, etc., which may be scanning or attacks.

Some attackers will first scan the directory structure to see if there are paths such as /admin and /backup . If you find such regular requests in your log, you have to be vigilant.

Basically that's it. IIS itself is powerful, but the default configuration is not necessarily safe. Adjust permissions according to actual business needs, close redundant services, add security heads, and regularly check logs. After these steps, you can block most common attack methods.

The above is the detailed content of Securing IIS Against Common Web Vulnerabilities. For more information, please follow other related articles on the PHP Chinese website!