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== Noncompliant Code Example

For https://docs.oracle.com/javase/9/docs/api/javax/xml/parsers/DocumentBuilderFactory.html[DocumentBuilder], https://docs.oracle.com/javase/9/docs/api/javax/xml/parsers/SAXParserFactory.html[SAXParser] and https://docs.oracle.com/javase/9/docs/api/javax/xml/validation/SchemaFactory.html[Schema] and https://docs.oracle.com/javase/9/docs/api/javax/xml/transform/TransformerFactory.html[Transformer] JAPX factories:

----
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, false); // Noncompliant

SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, false); // Noncompliant

SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, false); // Noncompliant

TransformerFactory factory = javax.xml.transform.TransformerFactory.newInstance(); 
factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, false); // Noncompliant
----

For https://dom4j.github.io/[Dom4j] library:

----
SAXReader xmlReader = new SAXReader();
xmlReader.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, false); // Noncompliant

----

For http://www.jdom.org/[Jdom2] library:

----
SAXBuilder builder = new SAXBuilder(); 
builder.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, false);  // Noncompliant
----

== Compliant Solution
For https://docs.oracle.com/javase/9/docs/api/javax/xml/parsers/DocumentBuilderFactory.html[DocumentBuilder], https://docs.oracle.com/javase/9/docs/api/javax/xml/parsers/SAXParserFactory.html[SAXParser] and https://docs.oracle.com/javase/9/docs/api/javax/xml/validation/SchemaFactory.html[Schema] and https://docs.oracle.com/javase/9/docs/api/javax/xml/transform/TransformerFactory.html[Transformer] JAPX factories:

----
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true); 

SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true); 

SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true); 

TransformerFactory factory = javax.xml.transform.TransformerFactory.newInstance(); 
factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true); 
----

For https://dom4j.github.io/[Dom4j] library:

----
SAXReader xmlReader = new SAXReader();
xmlReader.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true); 

----

For http://www.jdom.org/[Jdom2] library:

----
SAXBuilder builder = new SAXBuilder(); 
builder.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);  
----

== See

* https://docs.oracle.com/en/java/javase/13/security/java-api-xml-processing-jaxp-security-guide.html#GUID-8CD65EF5-D113-4D5C-A564-B875C8625FAC[Oracle Java Documentation] - XML External Entity Injection Attack
* https://www.owasp.org/index.php/Top_10-2017_A4-XML_External_Entities_(XXE)[OWASP Top 10 2017 Category A4] - XML External Entities (XXE)
* https://cheatsheetseries.owasp.org/cheatsheets/XML_External_Entity_Prevention_Cheat_Sheet.html#java[OWASP XXE Prevention Cheat Sheet]
* http://cwe.mitre.org/data/definitions/776.html[MITRE, CWE-776] - Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

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== Implementation Specification
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== Comments And Links
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