![]() ![]() The features can either be set on the factory or the underlying XMLReader setFeature method.Įach XML processor implementation has its own features that govern how DTDs and external entities are processed. The JAXP DocumentBuilderFactory setFeature method allows a developer to control which implementation-specific XML processor features are enabled or disabled. Only the DocumentBuilderFactory example is presented here. JAXP DocumentBuilderFactory, SAXParserFactory and DOM4J ¶ĭocumentBuilderFactory, SAXParserFactory and DOM4J XML Parsers can be configured using the same techniques to protect them against XXE. The following describes how to disable XXE in the most commonly used XML parsers for Java. To use these parsers safely, you have to explicitly disable XXE in the parser you use. Java applications using XML libraries are particularly vulnerable to XXE because the default settings for most Java XML parsers is to have XXE enabled. SAX2XMLReader * reader = XMLReaderFactory :: createXMLReader () parser -> setFeature ( XMLUni :: fgXercesDisableDefaultEntityResolution, true ) Java ¶ Use of XercesDOMParser do this to prevent XXE: Search for the usage of the following APIs to ensure there is no XML_PARSE_NOENT and XML_PARSE_DTDLOAD defined in the parameters: Per: According to this post, starting with libxml2 version 2.9, XXE has been disabled by default as committed by the following patch. XML_PARSE_DTDLOAD: Load the external DTD. ![]() ![]() XML_PARSE_NOENT: Expands entities and substitutes them with replacement text.The Enum xmlParserOption should not have the following options defined: If it is not possible to disable DTDs completely, then external entities and external document type declarations must be disabled in the way that's specific to each parser.ĭetailed XXE Prevention guidance for a number of languages and commonly used XML parsers in those languages is provided below. Spring Framework MVC/OXM XXE Vulnerabilitiesĭisabling DTDs also makes the parser secure against denial of services (DOS) attacks such as Billion Laughs. JAXP DocumentBuilderFactory, SAXParserFactory and DOM4J Insecure Direct Object Reference Prevention ![]()
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