6.8 - DSA-2842

Alvaro Munoz discovered a XML External Entity (XXE) injection in the Spring Framework which can be used for conducting CSRF and DoS attacks on other sites.

The Spring OXM wrapper did not expose any property for disabling entity resolution when using the JAXB unmarshaller. There are four possible source implementations passed to the unmarshaller:

DOMSource StAXSource SAXSource StreamSource

For a DOMSource, the XML has already been parsed by user code and that code is responsible for protecting against XXE.

For a StAXSource, the XMLStreamReader has already been created by user code and that code is responsible for protecting against XXE.

For SAXSource and StreamSource instances, Spring processed external entities by default thereby creating this vulnerability.

The issue was resolved by disabling external entity processing by default and adding an option to enable it for those users that need to use this feature when processing XML from a trusted source.

It was also identified that Spring MVC processed user provided XML with JAXB in combination with a StAX XMLInputFactory without disabling external entity resolution. External entity resolution has been disabled in this case.

For the stable distribution (wheezy), this problem has been fixed in version 3.0.6.RELEASE-6+deb7u1.

For the unstable distribution (sid), this problem has been fixed in version 3.0.6.RELEASE-10.

We recommend that you upgrade your libspring-java packages.