CVE-2009-2476 in OpenJDK
Summary
by MITRE
The Java Management Extensions (JMX) implementation in Sun Java SE 6 before Update 15, and OpenJDK, does not properly enforce OpenType checks, which allows context-dependent attackers to bypass intended access restrictions by leveraging finalizer resurrection to obtain a reference to a privileged object.
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Analysis
by VulDB Data Team • 08/13/2021
The vulnerability identified as CVE-2009-2476 represents a critical security flaw in the Java Management Extensions implementation within Sun Java SE 6 before update 15 and OpenJDK environments. This weakness stems from insufficient enforcement of OpenType checks within the JMX framework, creating a pathway for malicious actors to circumvent intended access controls. The vulnerability specifically exploits the interaction between the Java runtime's finalization mechanism and object reference management, allowing attackers to manipulate object lifecycles in ways that were not anticipated by the security model.
The technical root cause of this vulnerability lies in the improper handling of object references during the finalization process, which creates opportunities for privilege escalation through object resurrection techniques. When objects are finalized in Java, their references can be manipulated to maintain access to privileged resources even after the normal object lifecycle has completed. The flaw allows attackers to leverage this behavior to obtain references to objects that should normally be restricted, effectively bypassing the security boundaries that JMX is designed to enforce. This represents a classic example of a security bypass vulnerability where the intended access controls fail due to improper implementation of object lifecycle management.
The operational impact of CVE-2009-2476 is significant as it enables context-dependent attackers to gain unauthorized access to privileged management operations within Java applications. Attackers can exploit this vulnerability to perform actions that should be restricted to authorized administrators or system processes, potentially leading to complete system compromise. The vulnerability is particularly dangerous because it operates at the core of Java's management infrastructure, where it can provide attackers with extensive control over application behavior and system resources. This type of attack can result in data breaches, system infiltration, and the potential for further lateral movement within compromised networks.
This vulnerability maps to CWE-284, which describes improper access control in software systems, and aligns with ATT&CK technique T1068, which covers local privilege escalation through software exploitation. The attack vector leverages the Java runtime's object finalization mechanism to achieve unauthorized access, demonstrating how seemingly benign language features can create security vulnerabilities when not properly secured. Organizations running affected Java versions should prioritize immediate patching, as the vulnerability can be exploited remotely in many scenarios where JMX is exposed to untrusted networks. The remediation strategy involves applying the appropriate security updates from Oracle and OpenJDK, along with implementing network segmentation to limit exposure of JMX endpoints to trusted networks only.
The broader implications of this vulnerability highlight the complexity of securing modern application frameworks where multiple layers of security must work in harmony. The flaw demonstrates how security boundaries can be circumvented through unexpected interactions between different Java runtime features, emphasizing the importance of comprehensive security testing that considers object lifecycle management and finalization behaviors. This vulnerability serves as a reminder that even well-established security frameworks can contain implementation gaps that require careful attention during both development and deployment phases. Organizations should implement regular security assessments and maintain updated security configurations to prevent exploitation of similar vulnerabilities that may arise from complex interactions between Java runtime features and security controls.