Check Point Advisories

Ruby on Rails XML Processor YAML Deserialization Code Execution (CVE-2013-0156)

Vulnerability
Protection

Check Point Reference:	CPAI-2013-023
Date Published:	17 Jan 2013
Severity:	Critical
Last Updated:	Tuesday 03 November, 2015
Source:
Industry Reference:	CVE-2013-0156
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?
Vulnerability Description	A remote code execution vulnerability exists in Ruby on Rails. The vulnerability is due to automatically casting values from user-provided YAML and Symbol strings to certain data types without validating the input. The attacker connects to the target server and sends a specially crafted XML request containing an embedded YAML-encoded object to a Rails page. The vulnerability is triggered when the affected program processes the malicious request. Successful exploitation will result in arbitrary code execution within the context of service.

Protection Overview

This protection will detect and block attempts to exploit this vulnerability.

In order for the protection to be activated, update your Security Gateway product to the latest IPS update. For information on how to update IPS, go to SBP-2006-05, click on Protection tab and select the version of your choice.

Security Gateway R80 / R77 / R75

In the IPS tab, click Protections and find the Ruby on Rails XML Processor YAML Deserialization Code Execution protection using the Search tool and Edit the protection's settings.
Install policy on all Security Gateways.

This protection's log will contain the following information:

Attack Name: Web Server Enforcement Violation.
Attack Information: Ruby on Rails XML Processor YAML deserialization code execution