CVE-2002-2040 in RTOS
Summary
by MITRE
The (1) phrafx and (2) phgrafx-startup programs in QNX realtime operating system (RTOS) 4.25 and 6.1.0 do not properly drop privileges before executing the system command, which allows local users to execute arbitrary commands by modifying the PATH environment variable to reference a malicious crttrap program.
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Analysis
by VulDB Data Team • 11/29/2024
The vulnerability identified as CVE-2002-2040 affects the QNX real-time operating system versions 4.25 and 6.1.0, specifically targeting the phrafx and phgrafx-startup programs. This represents a classic privilege escalation flaw that exploits improper privilege handling during system command execution. The vulnerability stems from the failure of these programs to properly drop elevated privileges before invoking system commands, creating a dangerous execution path that local attackers can manipulate. The issue is particularly concerning in real-time operating system environments where security and predictability are paramount for system reliability.
The technical flaw manifests through the manipulation of the PATH environment variable, which allows attackers to redirect command execution to malicious binaries. When these programs execute system commands without properly dropping privileges, they inherit the elevated permissions of the calling process. This creates an opportunity for local users to substitute legitimate system binaries with malicious counterparts, specifically targeting the crttrap program that gets executed through the compromised PATH resolution. The vulnerability directly maps to CWE-276, which describes improper privilege management, and represents a classic case of insecure environment variable handling.
The operational impact of this vulnerability extends beyond simple command execution, as it enables full privilege escalation within the QNX RTOS environment. Local attackers can leverage this flaw to execute arbitrary code with elevated privileges, potentially compromising the entire system integrity. In real-time operating system contexts, this could lead to catastrophic failures in time-critical applications, as attackers might gain the ability to manipulate system resources, disrupt real-time scheduling, or access sensitive data. The vulnerability particularly affects systems where these programs are executed with elevated privileges, making it a significant concern for embedded systems and industrial control environments that rely on QNX for critical operations.
Mitigation strategies for CVE-2002-2040 should focus on implementing proper privilege management practices and environment variable validation. System administrators should ensure that the phrafx and phgrafx-startup programs properly drop privileges before executing any system commands, following the principle of least privilege. The PATH environment variable should be carefully controlled and validated to prevent unauthorized binary substitution, with hardcoded paths to system binaries being preferred over PATH-based resolution. Additionally, implementing proper access controls and monitoring for unauthorized modifications to system binaries would help detect potential exploitation attempts. This vulnerability aligns with ATT&CK technique T1068, which covers privilege escalation through insecure program execution, and emphasizes the importance of proper privilege separation in operating system security implementations.