Security Advisory

ZF2012-01: Local file disclosure via XXE injection in Zend_XmlRpc

Zend_XmlRpc is vulnerable to XML eXternal Entity (XXE) Injection attacks. The SimpleXMLElement class (SimpleXML PHP extension) is used in an insecure way to parse XML data. External entities can be specified by adding a specific DOCTYPE element to XML-RPC requests. By exploiting this vulnerability an application may be coerced to open arbitrary files and/or TCP connections.

Action Taken

The Request and Response implementations in Zend_XmlRpc were patched to ensure libxml_disable_entity_loader() is invoked prior to instantiating any SimpleXML objects. This disables XXE parsing, and thus disables the attack vector.

This patch has been applied starting in versions 1.11.12 and 1.12.0 of Zend Framework, and has been ported to the upcoming version 2.0.0 development branch (and will be included starting with the 2.0.0beta5 release).

Recommendations

If you are using either Zend_XmlRpc_Server or Zend_XmlRpc_Client in your projects, we recommend immediately upgrading to 1.11.12 or greater.

Update

Additional attack vectors were identified in Zend_Dom, Zend_Feed, and Zend_Soap, and patched in an identical manner.

The patches for these components are included in versions 1.11.13 and 1.12.0 of Zend Framework, and ported to the upcoming version 2.0.0 development branch (released with 2.0.0rc4). If you are using any of the affected components, we recommend upgrading to 1.11.13 or greater immediately.

Other Information

Acknowledgments

The Zend Framework team thanks the following for working with us to help protect its users:

Both from SEC Consult Vulnerability Lab (www.sec-consult.com).

Reporting Potential Security Issues

If you have encountered a potential security vulnerability in Zend Framework, please report it to us at zf-security@zend.com. We will work with you to verify the vulnerability and patch it.

When reporting issues, please provide the following information:

We request that you contact us via the email address above and give the project contributors a chance to resolve the vulnerability and issue a new release prior to any public exposure; this helps protect Zend Framework users and provides them with a chance to upgrade and/or update in order to protect their applications.

For sensitive email communications, please use our PGP key.

Policy

Zend Framework takes security seriously. If we verify a reported security vulnerability, our policy is:

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