How To Prevent Xml External Entity Injections

In the era of web applications and APIs, security has been a vital and top priority. We all know about different security breaches and injections in the web world, but have you ever heard about XML External Entity Injection or how to prevent it? It is a lesser-known yet critical version of a data breach. Let's understand the same in detail.

What is an XXE injection?

XXE injection is a cybersecurity threat at the application layer that attacks the vulnerabilities in XML parsing. An XML document consists of entities that point to external resources. If the application fails to validate the XML input, the attacker can easily create a malicious XML code and inject the same. This results in unauthorized access to personal information, sensitive server files, sensible networks, and other security vulnerabilities.

Potential impacts of XXE attacks?

• Attackers can get access to sensitive files from the server.
• Attackers can manipulate and send internal server requests to gain access to APIs or databases.
• The attack can cause the application to crash because of excessive resource injection.
• Critical system information disclosure is possible.

How to prevent XXE injection?

To prevent XXE injections, keep in mind the following:

1. Disable external entity processing:

The most effective and first line of defense is to turn off the external entity processing in your XML parser. This will prevent attacks and can be done with a simple configuration setting.

2.?A custom Web Application Firewall (WAF):

A WAF will defend the application layer and prevent any external source injection. It will detect any unknown incoming or outgoing traffic of websites. It will also filter all the known patterns of attacks and prevent and block any obvious XXE inputs.

3. Use Application Server Instrumentation (ASI):

ASI is a technology that monitors the overall activities of any web application and guards it by injecting checkpoints in the application code. It acts as a security sensor and gives your application real-time visibility to check every request and data transfer. Instrumentation is the most efficient and useful form of preventing XXE injection.

4. Limit application permissions:

If the application does not need specific files or resources, limit the permissions granted to access the same. This will limit the risk of XXE attacks.

Conclusion:

XXE attacks can have serious consequences for your web, but the right practice can help prevent them. As we all know, security is a continuous process, so try the best methods to prevent the attacks. Using safe libraries, monitoring the SML activities, validating the XML inputs, and keeping your application up to date can help prevent XXE injections.