CVE-2013-0269 in Mac OS X Server
Summary
by MITRE
The JSON gem before 1.5.5, 1.6.x before 1.6.8, and 1.7.x before 1.7.7 for Ruby allows remote attackers to cause a denial of service (resource consumption) or bypass the mass assignment protection mechanism via a crafted JSON document that triggers the creation of arbitrary Ruby symbols or certain internal objects, as demonstrated by conducting a SQL injection attack against Ruby on Rails, aka "Unsafe Object Creation Vulnerability."
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/01/2021
The CVE-2013-0269 vulnerability represents a critical security flaw in the JSON gem for Ruby applications, affecting versions prior to 1.5.5, 1.6.8, and 1.7.7 respectively. This vulnerability operates as an unsafe object creation vulnerability that enables remote attackers to manipulate the Ruby interpreter's symbol table and internal object creation mechanisms through carefully crafted JSON documents. The flaw stems from insufficient validation of JSON input during parsing operations, allowing attackers to inject malicious payloads that trigger unintended object creation patterns within the Ruby runtime environment.
The technical exploitation of this vulnerability occurs through the creation of arbitrary Ruby symbols and internal objects that consume excessive system resources, leading to denial of service conditions. When Ruby on Rails applications process JSON data containing specially crafted payloads, the JSON parser creates symbols that remain in memory indefinitely, causing memory exhaustion over time. Additionally, the vulnerability enables bypassing mass assignment protection mechanisms that are designed to prevent unauthorized modification of protected attributes in ActiveRecord models. This dual nature of the vulnerability allows attackers to both consume system resources and potentially execute SQL injection attacks against the underlying database systems.
The operational impact of CVE-2013-0269 extends beyond simple denial of service scenarios to encompass serious application security compromises. Organizations running Ruby on Rails applications that process untrusted JSON input become vulnerable to resource exhaustion attacks that can render applications unavailable to legitimate users. The mass assignment bypass capability creates additional attack vectors where attackers can manipulate database records through unauthorized attribute assignment, potentially leading to data corruption, unauthorized access, or complete system compromise. This vulnerability aligns with CWE-457: Use of Uninitialized Variable and CWE-770: Allocation of Resources Without Limits or Throttling, as it demonstrates improper resource management and insufficient input validation practices.
Security practitioners should implement immediate mitigations including upgrading the JSON gem to versions 1.5.5, 1.6.8, or 1.7.7 depending on their Ruby version requirements. Organizations must also deploy input validation controls at application boundaries and consider implementing rate limiting mechanisms to prevent resource exhaustion attacks. The vulnerability demonstrates characteristics consistent with attack patterns found in the MITRE ATT&CK framework under the T1499.004: Endpoint Denial of Service category, as well as T1213.002: Replication Through Removable Media, when considering the potential for persistent symbol creation attacks. Additional defensive measures should include monitoring for unusual symbol table growth patterns and implementing proper JSON schema validation to prevent exploitation of similar vulnerabilities in other components of the application stack.