Apple has released an additional security advisory and updated software to address the Ruby on Rails action pack parameter processing remote code execution vulnerability.
Description
Ruby on Rails contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code.
The vulnerability is due to improper implementation of parameter-parsing code in the affected software. An unauthenticated, remote attacker could exploit the vulnerability by submitting crafted XML or YAML (YAML Ain't Markup Language) parameters to the affected software. A successful exploit could allow the attacker to execute arbitrary code in the security context of the vulnerable application. If the vulnerable application holds elevated privileges, the attacker could completely compromise the targeted system.
Functional code that exploits this vulnerability is publicly available as part of the Metasploit Framework.
Ruby on Rails has confirmed the vulnerability in a security announcement and released software updates.
Warning Indicators
Ruby on Rails versions prior to 3.2.11, 3.1.10, 3.0.19, and 2.3.15 are vulnerable.
IntelliShield Analysis
To exploit the vulnerability, the attacker must submit malicious requests to the system. In a typical network configuration, the attacker must have access to trusted, internal networks to submit malicious requests to the system. This access requirement could reduce the likelihood of a successful exploit.
Ruby on Rails reports there is no fix for YAML object injection.Administrators are advised to immediately disable YAML parameter parsing if it has been enabled.
Due to the widespread deployment and usage of Ruby on Rails and the public availability of functional exploit code, Administrators are advised to upgrade or patch affected systems immediately.
Vendor Announcements
Ruby on Rails has released a security announcement and a release announcement at the following links:
An unauthenticated, remote attacker could exploit the vulnerability to execute arbitrary code in the security context of the vulnerable application. If the vulnerable application holds elevated privileges, the attacker could completely compromise the targeted system.
Technical Information
The vulnerability is due to insufficient validation and sanitization of user-supplied input to the parameter-parsing code in the affected software. The vulnerable code could allow a Ruby on Rails application to automatically cast values from strings to certain data types. The type casting code improperly supports certain conversions on user-supplied data which could result in symbol creation and YAML parsing.
An unauthenticated, remote attacker could exploit the vulnerability by submitting crafted parameters to the Ruby on Rails XML request processor. A successful exploit could allow the attacker to instantiate a remote object, which could execute arbitrary Ruby code in the security context of the vulnerable application. If the vulnerable application holds elevated privileges, the attacker could completely compromise the targeted system. Additionally, the attacker may be able to bypass authentication systems, inject arbitrary SQL or cause a targeted application to terminate abnormally, resulting in a denial of service (DoS) condition for legitimate users.
Safeguards
Administrators are advised to apply the appropriate updates.
Administrators may consider disabling XML parsing in the vulnerable applications.
Administrators may consider removing YAML and Symbol support from the XML parser if XML parsing functionality is required.
Administrators are advised to immediately disable YAML parameter parsing if it has been enabled. Ruby on Rails reports there is no fix for YAML object injection.
Administrators are advised to monitor affected systems.
Version 4, February 5, 2013, 05:45 AM: Apple has released a security advisory and updated software to address the Ruby on Rails action pack parameter processing remote code execution vulnerability
Version 3, January 14, 2013, 8:21 AM: Red Hat has released an additional security advisory and updated packages to address the ruby on rails action pack parameter processing remote code execution vulnerability.
Version 2, January 11, 2013, 6:52 AM: Red Hat has released a security advisory and updated packages to address the ruby on rails action pack parameter processing remote code execution vulnerability.
Version 1, January 10, 2013, 11:51 PM: Ruby on Rails contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code on a targeted system. Updates are available.
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FreeBSD Project
FreeBSD
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Red Hat CloudForms
x86 Base
Red Hat, Inc.
Red Hat OpenShift Enterprise
x86_64 Base
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1.0 x86_64 | 1.1 x86_64
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