Skip to content

Harden DocxReport and DOMUtils XML parsers against XXE #735

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
MarkLee131 wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Harden DocxReport and DOMUtils XML parsers against XXE #735

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
48 changes: 46 additions & 2 deletions ...pensagres.xdocreport.core/src/main/java/fr/opensagres/xdocreport/core/utils/DOMUtils.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,9 +32,11 @@
import java.util.Collection;
import java.util.Collections;

import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
Expand All @@ -53,10 +55,52 @@
public class DOMUtils
{

private static final String DISALLOW_DOCTYPE_DECL = "http://apache.org/xml/features/disallow-doctype-decl";

private static final String LOAD_EXTERNAL_DTD = "http://apache.org/xml/features/nonvalidating/load-external-dtd";

private static final String EXTERNAL_GENERAL_ENTITIES = "http://xml.org/sax/features/external-general-entities";

private static final String EXTERNAL_PARAMETER_ENTITIES = "http://xml.org/sax/features/external-parameter-entities";

/**
* Returns a {@link DocumentBuilderFactory} hardened against XXE: DOCTYPE declarations are
* rejected and external entities/DTDs are not resolved (CVE-2025-65482).
*/
public static DocumentBuilderFactory newSecureDocumentBuilderFactory()
throws ParserConfigurationException
{
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setFeature( DISALLOW_DOCTYPE_DECL, true );
factory.setFeature( EXTERNAL_GENERAL_ENTITIES, false );
factory.setFeature( EXTERNAL_PARAMETER_ENTITIES, false );
factory.setFeature( LOAD_EXTERNAL_DTD, false );
factory.setFeature( XMLConstants.FEATURE_SECURE_PROCESSING, true );
factory.setXIncludeAware( false );
factory.setExpandEntityReferences( false );
return factory;
}

/**
* Returns a {@link SAXParserFactory} hardened against XXE: DOCTYPE declarations are rejected
* and external entities/DTDs are not resolved (CVE-2025-65482).
*/
public static SAXParserFactory newSecureSAXParserFactory()
throws ParserConfigurationException, SAXException
{
SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setFeature( DISALLOW_DOCTYPE_DECL, true );
factory.setFeature( EXTERNAL_GENERAL_ENTITIES, false );
factory.setFeature( EXTERNAL_PARAMETER_ENTITIES, false );
factory.setFeature( LOAD_EXTERNAL_DTD, false );
factory.setFeature( XMLConstants.FEATURE_SECURE_PROCESSING, true );
return factory;
}

public static Document load( InputStream stream )
throws ParserConfigurationException, SAXException, IOException
{
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilderFactory factory = newSecureDocumentBuilderFactory();
factory.setNamespaceAware( true );
DocumentBuilder builder = factory.newDocumentBuilder();
return builder.parse( stream );
Expand All @@ -65,7 +109,7 @@ public static Document load( InputStream stream )
public static Document load( String xml )
throws ParserConfigurationException, SAXException, IOException
{
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilderFactory factory = newSecureDocumentBuilderFactory();
factory.setNamespaceAware( true );
DocumentBuilder builder = factory.newDocumentBuilder();
return builder.parse( IOUtils.toInputStream( xml, EncodingConstants.UTF_8.name() ) );
Expand Down
57 changes: 57 additions & 0 deletions ...docreport.core/src/test/java/fr/opensagres/xdocreport/core/utils/DOMUtilsXxeTestCase.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,57 @@
package fr.opensagres.xdocreport.core.utils;

import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.ByteArrayInputStream;
import java.nio.charset.StandardCharsets;

import javax.xml.parsers.SAXParser;

import org.junit.Test;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
* Regression test for the XXE hardening (incomplete fix of CVE-2025-65482): the secure
* factories returned by {@link DOMUtils} reject a DOCTYPE and do not resolve external entities.
*/
public class DOMUtilsXxeTestCase
{

private static final String XXE =
"<?xml version=\"1.0\"?>\n"
+ "<!DOCTYPE r [ <!ENTITY x SYSTEM \"file:///etc/hostname\"> ]>\n"
+ "<r>&x;</r>";

@Test
public void loadRejectsDoctype()
throws Exception
{
try
{
DOMUtils.load( new ByteArrayInputStream( XXE.getBytes( StandardCharsets.UTF_8 ) ) );
fail( "DOMUtils.load must reject a DOCTYPE" );
}
catch ( SAXException e )
{
assertTrue( e.getMessage() != null );
}
}

@Test
public void secureSAXParserRejectsDoctype()
throws Exception
{
SAXParser parser = DOMUtils.newSecureSAXParserFactory().newSAXParser();
try
{
parser.parse( new ByteArrayInputStream( XXE.getBytes( StandardCharsets.UTF_8 ) ), new DefaultHandler() );
fail( "Secure SAXParser must reject a DOCTYPE" );
}
catch ( SAXException e )
{
assertTrue( e.getMessage() != null );
}
}
}
4 changes: 2 additions & 2 deletions ...report.document.docx/src/main/java/fr/opensagres/xdocreport/document/docx/DocxReport.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,6 @@

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.SAXException;

Expand All @@ -53,6 +52,7 @@
import fr.opensagres.xdocreport.core.io.IEntryReaderProvider;
import fr.opensagres.xdocreport.core.io.IEntryWriterProvider;
import fr.opensagres.xdocreport.core.io.XDocArchive;
import fr.opensagres.xdocreport.core.utils.DOMUtils;
import fr.opensagres.xdocreport.document.AbstractXDocReport;
import fr.opensagres.xdocreport.document.docx.images.DocxImageRegistry;
import fr.opensagres.xdocreport.document.docx.preprocessor.DefaultStyle;
Expand Down Expand Up @@ -162,7 +162,7 @@ protected void onBeforePreprocessing( Map<String, Object> sharedContext, XDocArc
try
{
HyperlinkContentHandler contentHandler = new HyperlinkContentHandler();
SAXParser saxParser = SAXParserFactory.newInstance().newSAXParser();
SAXParser saxParser = DOMUtils.newSecureSAXParserFactory().newSAXParser();
saxParser.parse(preprocessedArchive.getEntryInputStream(relsEntryName), contentHandler);
if ( contentHandler.getHyperlinks() != null )
{
Expand Down
1 change: 1 addition & 0 deletions ...src/main/java/fr/opensagres/xdocreport/document/preprocessor/sax/SAXXDocPreprocessor.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,7 @@ public boolean preprocess( String entryName, InputStream reader, Writer writer,
{
XMLReader xmlReader = XMLReaderFactory.createXMLReader();
//To avoid xxe security issue
xmlReader.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
xmlReader.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
xmlReader.setFeature("http://xml.org/sax/features/external-general-entities", false);
xmlReader.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
Expand Down