Thanks. I changed the value to 1 but that made no difference -- the
exploit still works.

I can see that the JenaXMLInput class is related -- but I'm not sure
how it applies to my code if I'm not using XMLReader directly?
https://github.com/apache/jena/blob/main/jena-core/src/main/java/org/apache/jena/util/JenaXMLInput.java

Would a test case using RDFParser help?

On Sun, Nov 16, 2025 at 6:40 PM Andy Seaborne <[email protected]> wrote:
>
>
>  > System.setProperty("jdk.xml.entityExpansionLimit", "0");
>
> https://docs.oracle.com/javase/tutorial/jaxp/limits/limits.html
> "A value less than or equal to 0 indicates no limit."
>
>      Andy
>
> On 16/11/2025 16:44, Martynas Jusevičius wrote:
> > Hi,
> >
> > I want to protect my RDF/XML I/O code against Billion laughs, external
> > DTD and similar exploits. Using Jena 4.7.0.
> >
> > The reader code looks like this:
> >
> > public Model read(Model model, InputStream is, Lang lang, String
> > baseURI, ErrorHandler errorHandler)
> > {
> >      RDFParser parser = RDFParser.create().
> >          lang(lang).
> >          errorHandler(errorHandler).
> >          checking(true). // otherwise exceptions will not be thrown for
> > invalid URIs!
> >          base(baseURI).
> >          source(is).
> >          build();
> >
> >      parser.parse(StreamRDFLib.graph(model.getGraph()));
> >
> >      return model;
> > }
> >
> > I have a script that submits RDF/XML with Billion laughs (recursive
> > entity expansion) and that causes the Java application to run out of
> > memory:
> >
> > Caused by: java.lang.OutOfMemoryError: Java heap space
> > at java.base/java.util.Arrays.copyOf(Arrays.java:3537)
> > at 
> > java.base/java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:228)
> > at 
> > java.base/java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:740)
> > at java.base/java.lang.StringBuffer.append(StringBuffer.java:410)
> > at 
> > org.apache.jena.rdfxml.xmlinput.states.AbsWantLiteralValueOrDescription.characters(AbsWantLiteralValueOrDescription.java:62)
> > at 
> > org.apache.jena.rdfxml.xmlinput.states.WantLiteralValueOrDescription.characters(WantLiteralValueOrDescription.java:77)
> > at 
> > org.apache.jena.rdfxml.xmlinput.impl.XMLHandler.characters(XMLHandler.java:137)
> > at org.apache.xerces.parsers.AbstractSAXParser.characters(Unknown Source)
> > at org.apache.xerces.impl.dtd.XMLDTDValidator.characters(Unknown Source)
> > at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanContent(Unknown
> > Source)
> > at 
> > org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown
> > Source)
> > at 
> > org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown
> > Source)
> > at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
> > at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
> > at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
> > at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
> > at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
> > at 
> > org.apache.jena.rdfxml.xmlinput.impl.RDFXMLParser.parse(RDFXMLParser.java:96)
> > at org.apache.jena.rdfxml.xmlinput.ARP.load(ARP.java:118)
> > at 
> > org.apache.jena.riot.lang.ReaderRIOTRDFXML.parse(ReaderRIOTRDFXML.java:186)
> > at org.apache.jena.riot.lang.ReaderRIOTRDFXML.read(ReaderRIOTRDFXML.java:84)
> > at org.apache.jena.riot.RDFParser.read(RDFParser.java:416)
> > at org.apache.jena.riot.RDFParser.parseNotUri(RDFParser.java:406)
> > at org.apache.jena.riot.RDFParser.parse(RDFParser.java:356)
> > at com.atomgraph.core.io.ModelProvider.read(ModelProvider.java:113)
> > at com.atomgraph.core.io.ModelProvider.read(ModelProvider.java:96)
> > at com.atomgraph.core.io.ModelProvider.readFrom(ModelProvider.java:90)
> > at com.atomgraph.core.io.ModelProvider.readFrom(ModelProvider.java:53)
> > at 
> > org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$TerminalReaderInterceptor.invokeReadFrom(ReaderInterceptorExecutor.java:233)
> > at 
> > org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$TerminalReaderInterceptor.aroundReadFrom(ReaderInterceptorExecutor.java:212)
> > at 
> > org.glassfish.jersey.message.internal.ReaderInterceptorExecutor.proceed(ReaderInterceptorExecutor.java:132)
> > at 
> > org.glassfish.jersey.message.internal.MessageBodyFactory.readFrom(MessageBodyFactory.java:1072)
> >
> > I have tried the following config (and its alternative in
> > CATALINA_OPTS), but they do not seem to have any effect -- the exploit
> > still works:
> >
> > System.setProperty("javax.xml.stream.isSupportingExternalEntities", 
> > "false");
> > System.setProperty("javax.xml.accessExternalDTD", "");
> > System.setProperty("javax.xml.accessExternalSchema", "");
> > System.setProperty("jdk.xml.entityExpansionLimit", "0");
> >
> > What is the solution here?
> > I would hate to have to single out RDF/XML and handle it specially,
> > but I'll do it if it's necessary in order to solve this.
> >
> > Thanks.
> >
> > Martynas
> > atomgraph.com
>

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