XML External Entity (XXE) Injection Affecting org.springframework.ws:spring-xml package, versions [,4.1.4)[5.0.0-M1,5.0.2)

org.springframework.ws:spring-xml is a dependency of org.springframework.ws.

Affected versions of this package are vulnerable to XML External Entity (XXE) Injection via the Jaxp13XPathTemplate class in Jaxp13XPathTemplate.java. When XPath expressions are evaluated against StreamSource and SAXSource inputs, the template parses the XML through XPath.evaluate(String, InputSource, QName), which uses the JDK's default DocumentBuilderFactory and bypasses spring-xml's hardened parser configuration. As a result, external entity references in attacker-controlled XML are resolved during parsing. An attacker who can supply or influence the XML evaluated by an application can exploit XML External Entity (XXE) processing to read confidential local files or trigger server-side request forgery (SSRF) through external entities, depending on parser and platform behavior.

Note:

This is only exploitable if the application evaluates XPath over data controlled or influenced by remote users using the affected StreamSource or SAXSource types without an additional hardening layer.

XXE Injection is a type of attack against an application that parses XML input. XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. By default, many XML processors allow specification of an external entity, a URI that is dereferenced and evaluated during XML processing. When an XML document is being parsed, the parser can make a request and include the content at the specified URI inside of the XML document.

Attacks can include disclosing local files, which may contain sensitive data such as passwords or private user data, using file: schemes or relative paths in the system identifier.

For example, below is a sample XML document, containing an XML element- username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
   <username>John</username>
</xml>

An external XML entity - xxe, is defined using a system identifier and present within a DOCTYPE header. These entities can access local or remote content. For example the below code contains an external XML entity that would fetch the content of /etc/passwd and display it to the user rendered by username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
   <!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
   <username>&xxe;</username>
</xml>

Other XXE Injection attacks can access local resources that may not stop returning data, possibly impacting application availability and leading to Denial of Service.

• GitHub Commit
• Spring Security Advisory