CVE-2013-0333 in Ruby on Rails
Summary
by MITRE
lib/active_support/json/backends/yaml.rb in Ruby on Rails 2.3.x before 2.3.16 and 3.0.x before 3.0.20 does not properly convert JSON data to YAML data for processing by a YAML parser, which allows remote attackers to execute arbitrary code, conduct SQL injection attacks, or bypass authentication via crafted data that triggers unsafe decoding, a different vulnerability than CVE-2013-0156.
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Analysis
by VulDB Data Team • 12/22/2024
The vulnerability identified as CVE-2013-0333 represents a critical security flaw in the Ruby on Rails framework that specifically affects versions prior to 2.3.16 and 3.0.20. This issue resides within the active_support/json/backends/yaml.rb component which handles the conversion of JSON data into YAML format for processing. The flaw stems from improper handling of data conversion between these two markup languages, creating a dangerous attack surface that can be exploited by remote adversaries. The vulnerability is particularly concerning because it allows attackers to execute arbitrary code, conduct SQL injection attacks, and bypass authentication mechanisms through carefully crafted data inputs that trigger unsafe decoding operations.
The technical root cause of this vulnerability lies in the insufficient sanitization and validation of JSON data during the conversion process to YAML format. When Ruby on Rails processes JSON input and attempts to convert it to YAML for further processing, the framework fails to properly escape or validate special characters and data structures that could be interpreted as executable code within the YAML parser. This improper handling creates a path for attackers to inject malicious content that gets processed by the YAML parser, which is known to be vulnerable to object instantiation attacks. The flaw is distinct from CVE-2013-0156, indicating it represents a separate code path or implementation issue, yet it shares similar dangerous outcomes in terms of code execution capabilities.
The operational impact of this vulnerability is severe and multifaceted, affecting organizations running affected versions of Ruby on Rails applications. Remote attackers can exploit this vulnerability to execute arbitrary code on vulnerable systems, potentially leading to complete system compromise and data breaches. The ability to conduct SQL injection attacks through this vector means that attackers can manipulate database queries and extract sensitive information from backend databases. Additionally, the authentication bypass capability allows unauthorized access to protected application features and user accounts. The vulnerability affects the core functionality of Rails applications that rely on JSON to YAML conversion, making it particularly dangerous for web applications that process user input through these pathways.
Organizations should immediately implement mitigations including upgrading to patched versions of Ruby on Rails 2.3.16 or 3.0.20, which contain the necessary fixes for this vulnerability. System administrators should also consider implementing input validation and sanitization measures at application boundaries to reduce the risk of exploitation. The vulnerability aligns with CWE-20 Improper Input Validation and follows patterns similar to those described in ATT&CK technique T1059 Command and Scripting Interpreter, where attackers leverage application parsing vulnerabilities to execute malicious code. Security teams should also monitor for indicators of compromise related to YAML parsing attacks and implement network-based intrusion detection systems to identify exploitation attempts targeting this specific vulnerability. Organizations using older unsupported versions of Rails should plan migration to supported releases as soon as possible to ensure continued protection against similar vulnerabilities.