Java and Xerces: can't find property XMLConstants.ACCESS_EXTERNAL_DTD

Question

I looked for similar posts on this blog, but couldn't find an answer to my question, so I decided to ask for help.

I wrote this simple function in Java:

 public void open(InputStream stream) throws FoliumFatalException {
        try {
            InputSource is = new InputSource(stream);
            DocumentBuilderFactory dfact = DocumentBuilderFactory.newInstance();
            
//            /* OWASP: inhibit access to External Entities */
            dfact.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, ""); 
            dfact.setAttribute(XMLConstants.ACCESS_EXTERNAL_SCHEMA, ""); 
            
            _doc = dfact.newDocumentBuilder().parse(is);

        } catch (Throwable t) {
            _logger.error(t, t);
            throw new FoliumFatalException("ENG-0017", "Errore di parsing su stream", t);
        }

    }

My goal is applying OWASP standards as exposed here, but I get the following error:

 java.lang.IllegalArgumentException: Property 'http://javax.xml.XMLConstants/property/accessExternalDTD' is not recognized.
java.lang.IllegalArgumentException: Property 'http://javax.xml.XMLConstants/property/accessExternalDTD' is not recognized.
    at org.apache.xerces.jaxp.DocumentBuilderFactoryImpl.setAttribute(Unknown Source) ~[xercesImpl-2.8.0.jar:?]
    at agora.folium.engine.impl.j2ee.FoliumJ2eeXmlParserImpl.open(FoliumJ2eeXmlParserImpl.java:108) [classes/:?]
    at agora.folium.engine.impl.FoliumAbstractEngine.loadServices(FoliumAbstractEngine.java:268) [classes/:?]
    at agora.folium.engine.impl.j2ee.FoliumJ2eeEngineImpl.startup(FoliumJ2eeEngineImpl.java:110) [classes/:?]
    at agora.folium.engine.Folium.startup(Folium.java:258) [classes/:?]
    at agora.folium.control.impl.j2ee.FoliumActionServlet.init(FoliumActionServlet.java:94) [classes/:?]
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1230) [catalina.jar:7.0.85]
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1174) [catalina.jar:7.0.85]
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1066) [catalina.jar:7.0.85]
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5370) [catalina.jar:7.0.85]
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5668) [catalina.jar:7.0.85]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145) [catalina.jar:7.0.85]
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:1015) [catalina.jar:7.0.85]
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:991) [catalina.jar:7.0.85]
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652) [catalina.jar:7.0.85]
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:712) [catalina.jar:7.0.85]
    at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:2002) [catalina.jar:7.0.85]
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_141]
    at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_141]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_141]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_141]
    at java.lang.Thread.run(Unknown Source) [?:1.8.0_141]

I'm using Eclipse Oxygen, Tomcat 7 and Java 1.8.

`xercesImpl-2.8.0.jar:?`? Do you have a copy of Xerces in your web app? — nitind, Nov 14 '18 at 16:03
yes, I have. I even tried to change priorities in Eclipse Build Path Section, using XercesImpl before JRE System Library. — Bia, Nov 15 '18 at 11:54
That might work for a regular Java application, but Tomcat has to load classes from you web app's jars. Tricks like that won't work. — nitind, Nov 16 '18 at 22:21
You can check the answer provided in this [post](https://stackoverflow.com/questions/60190084/android-studio-cant-find-property-xmlconstants-access-external-dtd/60253367#60253367) — Chamlal, Feb 17 '20 at 12:12

score 11 · Answer 1 · answered Jun 08 '20 at 12:00

11

javax.xml.XMLConstants.ACCESS_EXTERNAL_DTD is defined in JAXP 1.5, but Xerces does not support it. If you can't remove Xerces dependency, you should add another implementation to your classpath before Xerces.

Alternatively, since JDK contains an implementation of Xerces you can configure DocumentBuilderFactory to return the JDK version using System.properties.

System.setProperty("javax.xml.parsers.DocumentBuilderFactory",
        "com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl");

answered Jun 08 '20 at 12:00

Cray

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this is related to https://stackoverflow.com/questions/45152707/transformerfactory-and-xalan-dependency-conflict so aoviding xerces and setting the DocumentBuilderFactory may also help, which it did in my case. – Gregor Feb 08 '21 at 13:20

score 6 · Answer 2 · answered Jul 24 '20 at 06:02

The issue is coming due to Xerces/XercesImpl in classpath. Xerces doesn't provide support for ACCESS_EXTERNAL_DTD property.

Solution 1. If possible, remove xerces jar from the class path.

Solution 2. Use JDK default implementation

DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance("com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl", null);

score 3 · Answer 3 · answered Nov 23 '18 at 20:11

Apache Xerces-J 2.12.0 and earlier implement older versions of JAXP that do not support either of the properties that you are trying to set. To block access to external entities, you could write an EntityResolver (that always throws a SAXException) and register that EntityResolver with the DocumentBuilder. See documentation here [1].

[1] http://xerces.apache.org/xerces2-j/javadocs/api/javax/xml/parsers/DocumentBuilder.html#setEntityResolver(org.xml.sax.EntityResolver)

score 0 · Answer 4 · edited Feb 23 '21 at 15:31

Our Java project was being built with Maven. As the team decided to integrate SonarQube in the pipeline, we faced something similar. "SonarQube doesn't run your tests or generate reports. It only imports pre-generated reports" (more on that here). In the case of Java/Kotlin/Scala/JVM, SonarQube needs some "JaCoCo XML coverage report". So, we had to add a dependency to our pom.xml:

<dependency>
  <groupId>org.jacoco</groupId>
  <artifactId>jacoco-maven-plugin</artifactId>
  <version>${jacoco.version}</version>
</dependency>

After some tweaking, we had it all up and running. But some tests were failing with "java.lang.IllegalArgumentException: Property 'http://javax.xml.XMLConstants/property/accessExternalDTD' is not recognized. at org.apache.xerces.jaxp.DocumentBuilderFactoryImpl.setAttribute(Unknown Source)...".

Long story short, the solution was to leave xerces out of the picture, as already stated in other answers:

<dependency>
  <groupId>org.jacoco</groupId>
  <artifactId>jacoco-maven-plugin</artifactId>
  <version>${jacoco.version}</version>
  <exclusions>
    <exclusion>
      <groupId>xerces</groupId>
      <artifactId>xercesImpl</artifactId>
    </exclusion>
  </exclusions>
</dependency>

Java and Xerces: can't find property XMLConstants.ACCESS_EXTERNAL_DTD

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