Unsanitized user input in XML External Entity

• Rule ID: php_lang_xml_external_entity_vulnerability
• Languages: php
• Source: xml_external_entity_vulnerability.yml

Description

Unsanitized user input in XML External Entity (XXE) processing can lead to security vulnerabilities. When your application parses XML input containing untrusted data, it may interpret URIs that point to unauthorized external resources. This can result in an XXE injection, compromising the security of your application.

Remediations

• Do not enable the parsing of external entities within your XML processing. Disabling the parsing of external entities prevents your application from attempting to access or include external resources based on untrusted input. For LibXML, for example, do not use the LIBXML_NOENT flag

  $userInput = $_GET["untrusted"];
  DOMDocument::loadXML($userInput, LIBXML_NOENT); // unsafe

References

• OWASP XML External Entity (XXE) prevention cheat sheet

Associated CWE

• CWE-611: Improper Restriction of XML External Entity Reference

OWASP Top 10

• A05:2021 - Security Misconfiguration

Configuration

To skip this rule during a scan, use the following flag

bearer scan /path/to/your-project/ --skip-rule=php_lang_xml_external_entity_vulnerability

To run only this rule during a scan, use the following flag

bearer scan /path/to/your-project/ --only-rule=php_lang_xml_external_entity_vulnerability