XML External Entities (XXE) Template

Executive Summary:

This report outlines an XML External Entities (XXE) vulnerability discovered within our application. XXE is a type of attack that exploits the way XML processors parse and interpret external entities, leading to potential data disclosure, server-side request forgery (SSRF), or denial-of-service (DoS) attacks. The report aims to provide a clear understanding of the vulnerability, its potential impact on our systems and users, and actionable recommendations for mitigation.

Description of the Vulnerability:

XML External Entities (XXE) vulnerability arises when the application processes XML input from untrusted sources without disabling external entity references. Attackers can leverage this vulnerability to include external entities, such as files or URLs, leading to various security risks, including information disclosure, server-side request forgery (SSRF), or denial-of-service (DoS) attacks.


Exploiting this vulnerability could result in sensitive data leakage, unauthorized access to internal resources, or disruption of service. Depending on the severity of the XXE vulnerability and the attacker's capabilities, the impact may range from data theft to complete system compromise.


The likelihood of XXE exploitation depends on the application's architecture, the presence of XML processing functionalities, and the attacker's intent. However, given the prevalence of XXE vulnerabilities in applications that handle XML input, the risk associated with this vulnerability is significant if not properly addressed.

Steps to Reproduce:

  1. Craft a malicious XML payload containing an external entity reference.
  2. Submit the crafted XML payload to the vulnerable endpoint of the application.
  3. Observe the application's response to determine if the external entity was successfully processed.
  4. Exploit the XXE vulnerability to perform actions such as reading sensitive files, initiating SSRF attacks, or causing denial-of-service.

Recommendations for Developers:

  1. Disable External Entities: Configure XML parsers to disable external entity processing entirely or restrict them to a trusted whitelist of entities. This prevents attackers from injecting arbitrary entities into XML documents and mitigates XXE vulnerabilities.
  2. Use Safe Parsing Libraries: Utilize XML parsing libraries or frameworks that have built-in protections against XXE attacks, such as disabling external entity resolution by default or providing secure APIs for XML processing.


Addressing the XXE vulnerability promptly is essential to mitigate the associated risks and protect our systems and users from potential exploitation. By implementing the recommended measures, we can enhance the security posture of our application and prevent unauthorized access or data leakage through XML processing vulnerabilities.