What does a XXE result from?
XXE vulnerabilities are caused by the configuration of XML parsers. XML parsers that work with web servers often allow you to use XML entities from external sources. An attacker may abuse this mechanism to include malicious content or access sensitive information.
What does XXE refer to?
XML external entity injection (also known as XXE) is a web security vulnerability that allows an attacker to interfere with an application’s processing of XML data.
Is XXE common?
OWASP rates the prevalence of XXE vulnerabilities as medium. It is not the most common OWASP category, but the severance is high which still places it high up on the Top 10 list.
Where can I find XXE?
Where to look for XXE?
- XML APIs.
- SOAP APIs.
- Anywhere that a Microsoft office (docx/xlxs/pptx/etc.) file is parsed.
- RSS feed parsers (RSS feeds are just XML)
- SAML Authentication.
- HTML parsing (for example, converting HTML to a PDF)
- Functionality that parses sitemap. xml files.
- Functionality that parses SVG files.
What can XXE do?
XXE enables an entity to be defined based on the content of a file path or URL. When the server reads the XML attack payload, it parses the external entity, merges it into the final document, and returns it to the user with the sensitive data inside.
What is XXE prevention?
XXE Prevention in Java Hackers using XXE attacks love Java as most Java XML parsers are vulnerable to XXE, thus making life difficult for you. For example, one of the most popular Java parsers dom4j, used to have XXE vulnerability and it’s very likely that most Java applications are still vulnerable to it.
What is XXE how do you prevent it?
General Guidance. The safest way to prevent XXE is always to disable DTDs (External Entities) completely. Depending on the parser, the method should be similar to the following: factory. setFeature(“http://apache.org/xml/features/disallow-doctype-decl”, true);
How long has XXE been around?
XXE vulnerability has been around since the early 2000s and despite its medium prevalence, it was included in the OWASP Top 10 at #4 in 2017 owing to the popularity of its underlying vector – XML and the high risk attached to most XML parsers.
What is blind XXE?
What is blind XXE? Blind XXE vulnerabilities arise where the application is vulnerable to XXE injection but does not return the values of any defined external entities within its responses.
What is XXE payload?
XML External Entity or XXE Injection Payloads XXE Attack Type Description Exploiting XXE to Retrieve Files Where an external entity containing the contents of a file is defined and returned in the response of the application.
How XXE injection is mitigated?
In most cases, XXE attacks can easily be prevented by disabling features making the XML processor weak and the application vulnerable. By analyzing the XML parsing library of the application, features that can be misused can be identified and disabled. DTD and XML external entity features must be disabled.
What is XXE medium?
XXE injection is a type of web security vulnerability that allows an attacker to interfere with the way an application processes XML data. Successful exploitation allows an attacker to view files from the application’s server and interact with any external or backend systems that the application can access.
What is an XML used for?
XML (Extensible Markup Language) is used to describe data. The XML standard is a flexible way to create information formats and electronically share structured data via the public internet, as well as via corporate networks.