CVE-2018-12539 in OpenJ9
Summary
by MITRE
In Eclipse OpenJ9 version 0.8, users other than the process owner may be able to use Java Attach API to connect to an Eclipse OpenJ9 or IBM JVM on the same machine and use Attach API operations, which includes the ability to execute untrusted native code. Attach API is enabled by default on Windows, Linux and AIX JVMs and can be disabled using the command line option -Dcom.ibm.tools.attach.enable=no.
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Analysis
by VulDB Data Team • 05/02/2023
The vulnerability described in CVE-2018-12539 represents a significant security flaw within the Eclipse OpenJ9 JVM implementation that undermines the principle of least privilege and process isolation. This issue affects version 0.8 of the Eclipse OpenJ9 runtime environment and stems from improper access controls within the Java Attach API implementation. The flaw allows unauthorized users to establish connections to running JVM processes and execute potentially malicious operations through the Attach API mechanisms, creating a serious attack surface that could be exploited by local adversaries.
The technical root cause of this vulnerability lies in the default configuration of the Java Attach API which is designed to enable dynamic attachment of tools and agents to running Java processes. In the affected Eclipse OpenJ9 implementation, the API operates with insufficient permission checks that permit any user on the system to connect to JVM processes owned by different users. This misconfiguration violates fundamental security principles and creates a privilege escalation vector where a low-privileged user can leverage the Attach API to execute untrusted native code within the context of a higher-privileged process. The vulnerability is particularly concerning because it affects multiple operating systems including Windows, Linux, and AIX, making it broadly exploitable across different environments.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and data exfiltration capabilities. An attacker with local access can use the Attach API to inject malicious agents into running JVM processes, potentially leading to remote code execution, privilege escalation, or information disclosure. The ability to execute untrusted native code through the Attach API creates a pathway for attackers to bypass traditional security controls and potentially gain full system control. This vulnerability particularly affects environments where multiple users share the same system and where JVM processes are running with elevated privileges or access to sensitive data. The default enablement of the Attach API on all supported platforms means that systems are inherently vulnerable unless explicitly configured to disable this functionality.
Organizations can mitigate this vulnerability through several defensive measures that align with established security frameworks and best practices. The primary mitigation involves explicitly disabling the Attach API using the command line option -Dcom.ibm.tools.attach.enable=no as recommended in the vulnerability description. This approach directly addresses the root cause by preventing unauthorized attachment operations and aligns with the principle of least privilege. Security configurations should also include proper user access controls and process isolation measures to limit the potential impact of any successful exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and process injection, while from a CWE perspective it represents a weakness in access control mechanisms and improper privilege management. Regular security audits and monitoring of JVM process attachment activities should be implemented to detect any unauthorized access attempts, and system administrators should ensure that all JVM installations are properly configured with appropriate security controls to prevent unauthorized users from leveraging this functionality.