CVE-2002-2039 in RTOS
Summary
by MITRE
/bin/su in QNX realtime operating system (RTOS) 4.25 and 6.1.0 allows local users to obtain sensitive information from core dump files by sending the SIGSERV (invalid memory reference) signal.
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Analysis
by VulDB Data Team • 11/29/2024
The vulnerability identified as CVE-2002-2039 affects the QNX real-time operating system versions 4.25 and 6.1.0, specifically targeting the /bin/su binary responsible for privilege escalation. This issue represents a critical information disclosure flaw that stems from improper handling of core dump generation when the system receives a SIGSERV signal. The QNX RTOS, designed for embedded systems and real-time applications, typically operates in environments where security and reliability are paramount, making such vulnerabilities particularly concerning for mission-critical deployments. The flaw exists within the core dump mechanism of the su command, which is fundamental to Unix-like systems for switching user identities.
The technical implementation of this vulnerability involves the interaction between the signal handling mechanism and core dump generation within the QNX environment. When a local user sends a SIGSERV signal to the su process, the system's core dump generation routine fails to properly sanitize memory contents before writing them to disk. This results in sensitive information such as authentication credentials, memory addresses, or other confidential data being inadvertently exposed in the core dump file. The vulnerability is classified under CWE-200 as "Information Exposure" and specifically relates to improper handling of sensitive data in core dumps, which can be exploited by local attackers with minimal privileges to gain access to information that should remain protected. The attack vector is straightforward requiring only local execution privileges and the ability to send signals to running processes.
The operational impact of this vulnerability extends beyond simple information disclosure, as the exposed data in core dump files can provide attackers with significant insights into the system's internal state and security mechanisms. Core dump files generated by the vulnerable su binary may contain memory segments that include passwords, cryptographic keys, or other sensitive material that could be used to escalate privileges or launch further attacks. In embedded systems running QNX RTOS, where resources are often limited and security considerations are paramount, such information exposure can compromise the integrity of the entire system. The vulnerability affects environments where the su command is frequently used for administrative tasks, making it a persistent threat in any deployment where user privilege escalation is required.
Mitigation strategies for CVE-2002-2039 should focus on both immediate system hardening and long-term architectural improvements. System administrators should ensure that core dump generation is properly configured to avoid storing sensitive information, which aligns with ATT&CK technique T1005 for "Data from Local System" and T1068 for "Exploitation for Privilege Escalation." The most effective immediate solution involves patching the QNX RTOS to version 6.2.0 or later, where the core dump handling has been properly addressed. Additionally, implementing proper signal handling mechanisms and restricting core dump generation for sensitive binaries can significantly reduce the attack surface. System monitoring should be enhanced to detect unusual core dump generation patterns, and access controls should be tightened around core dump directories to prevent unauthorized access to potentially sensitive information. The vulnerability also highlights the importance of following secure coding practices in real-time operating systems, particularly regarding memory management and signal handling, which are fundamental requirements for maintaining system security in embedded environments.