Memcached Cache Penetration (How to Avoid Malicious Requests)

Cache penetration refers to a security issue where malicious requests bypass the cache system in an application to retrieve data, thereby causing security vulnerabilities.

What is Cache Penetration?

Cache penetration is an attack method that allows attackers to directly access the required data from the cache system by setting a special domain name or IP address. This situation often occurs in web applications using memcached because memcached does not have default Same-Origin Policy restrictions.

How to Avoid Cache Penetration?

1. Use Same-Origin Policy

To prevent cache penetration, the application should be configured under the same domain, or the Same-Origin Policy should be set so that only requests from the same domain can access the cache system.

2. Use Host Header

Using the Host Header allows you to control which domain to retrieve the cache from, helping to protect your application from malicious requests.

3. Set Cache-Control

By setting Cache-Control headers, you can control the behavior of the cache system, limiting the ability to directly access a specific URL to avoid cache penetration.

4. Use Content Security Policy (CSP)

Using CSP allows you to explicitly define which domains are safe and can prevent malicious requests from accessing data.

5. Test and Verify

Regularly test your application for cache penetration attacks and perform relevant security validations to ensure your application is adequately protected.