Documentbuilderfactory setvalidating dtd
XML e Xternal Entity injection (XXE) is a type of attack against an application that parses XML input.This attack occurs when untrusted XML input containing a reference to an external entity is processed by a weakly configured XML parser.This attack may lead to the disclosure of confidential data, denial of service, Server Side Request Forgery (SSRF), port scanning from the perspective of the machine where the parser is located, and other system impacts.
If it is not possible to disable DTDs completely, then external entities and external doctypes must be disabled in the way that’s specific to each parser.
Unmarshaller parses XML and does not support any flags for disabling XXE, it’s imperative to parse the untrusted XML through a configurable secure parser first, generate a source object as a result, and pass the source object to the Unmarshaller.
For example: SAXParser Factory spf = SAXParser Instance(); Feature(" false); Feature(" false); Feature(" false); Source xml Source = new SAXSource(SAXParser()XMLReader(), new Input Source(new String Reader(xml))); JAXBContext jc = Instance(Object.class); Unmarshaller um = jc.create Unmarshaller(); um.unmarshal(xml Source); A xpath.
SUPPORT_DTD, false); // This disables DTDs entirely for that factory xml Input Property("Supporting External Entities", false); // disable external entities Schema Factory factory = Schema Instance(" Schema schema = Schema(); Validator validator = Validator(); Property(XMLConstants. ACCESS_EXTERNAL_SCHEMA, ""); Schema Factory factory = Schema Instance(" Property(XMLConstants. ACCESS_EXTERNAL_SCHEMA, ""); Schema schema = Schema(Source); SAXTransformer Factory sf = SAXTransformer Instance(); Attribute(XMLConstants. ACCESS_EXTERNAL_STYLESHEET, ""); XMLFilter(Source); XMLReader reader = XMLReader Factory.create XMLReader(); Feature(" true); Feature(" false); // This may not be strictly required as DTDs shouldn't be allowed at all, per previous line.
Feature(" false); Feature(" false); sax Feature(" true); sax Feature(" false); sax Feature(" false); SAXBuilder builder = new SAXBuilder(); Feature(" Feature(" false); Feature(" false); Document doc = builder.build(new File(file Name)); Since a bind.