CVE-2013-4152 XML External Entity (XXE) injection in Spring Framework

[Pivotal Security Team <security@xxxxxxxxxxxxx>]

Severity: Important

Vendor: Spring by Pivotal

Versions Affected:
- 3.0.0 to 3.2.3 (Spring OXM & Spring MVC)
- 4.0.0.M1 (Spring OXM)
- 4.0.0.M1-4.0.0.M2 (Spring MVC)
- Earlier unsupported versions may also be affected

Description:
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.


Mitigation:
Users of affected versions should apply the following mitigation:
- Users of 3.x should upgrade to 3.2.4 or later
- Users of 4.x should upgrade to 4.0.0.RC1 or later once released
Note the Spring OXM issue is fixed in 4.0.0.M2

Credit:
These issues were identified by Alvaro Munoz of the HP Enterprise Security Team.

References:
http://www.gopivotal.com/security/cve-2013-4152
https://github.com/SpringSource/spring-framework/pull/317 (Spring OXM)
https://jira.springsource.org/browse/SPR-10806 (Spring MVC)

History:
2013-Aug-22: Initial vulnerability report published.