PT-2013-14: XML External Entities Injection in PHP

Vulnerable software

PHP
Version: 5.4.12/5.3.22 and earlier

Application link:
http://php.net/

Severity level

Severity level: Medium
Impact: XML External Entities Injection (XXE)
Access Vector: Remote

CVSS v2:
Base Score: 5.0
Vector: (AV:N/AC:L/Au:N/C:P/I:N/A:N)

CVE: CVE-2013-1643

Software description

PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML.

Vulnerability description

The specialists of Positive Technologies have detected an "XXE" vulnerability in PHP.

The vulnerability was detected in the PHP's built-in SoapClient and SoapServer classes. PHP allows the use of external entities while parsing SOAP wsdl files which allows an attacker to read arbitrary files. If a web application unserializes user-supplied data and tries to execute any method of it, an attacker can send serialized SoapClient object initialized in non-wsdl mode which will make PHP to parse automatically remote XML-document specified in the "location" option parameter.

How to fix

Update your software up to the latest version.

Advisory status

07.02.2013 - Vendor gets vulnerability details
14.03.2013 - Vendor releases fixed version and details
19.03.2013 - Public disclosure

Credits

The vulnerability was discovered by Arseniy Reutov, Positive Research Center (Positive Technologies Company)

References

http://en.securitylab.ru/lab/PT-2013-14

Reports on the vulnerabilities previously discovered by Positive Research:

http://ptsecurity.com/research/advisory/
http://en.securitylab.ru/lab/

Threatscape