CVE-2006-0621 in RTOS
Summary
by MITRE
Multiple buffer overflows in QNX Neutrino RTOS 6.2.0 allow local users to execute arbitrary code via a long first argument to the (1) su or (2) passwd commands.
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Analysis
by VulDB Data Team • 07/18/2018
The vulnerability identified as CVE-2006-0621 represents a critical security flaw in QNX Neutrino RTOS version 6.2.0 that exposes the system to local privilege escalation attacks through buffer overflow conditions in fundamental system utilities. This vulnerability specifically affects the su and passwd commands, which are essential for user authentication and privilege management within the operating system. The flaw stems from inadequate input validation mechanisms that fail to properly handle excessively long first arguments, creating exploitable buffer overflow conditions that can be leveraged by local attackers to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability manifests through improper bounds checking in the command line argument processing of the su and passwd utilities. When a local user provides an overly long first argument to either command, the system fails to validate the input length against predetermined buffer boundaries, resulting in memory corruption that can be exploited to overwrite critical program execution structures. This type of vulnerability falls under the CWE-121 category of buffer overflow conditions, specifically representing a stack-based buffer overflow that occurs when the program writes beyond the allocated buffer space on the stack. The attack vector is particularly dangerous because it targets commands that are frequently used for privilege management and user authentication, making it an attractive target for attackers seeking to escalate their privileges within the system.
The operational impact of this vulnerability extends beyond simple code execution capabilities, as it fundamentally undermines the security model of the QNX Neutrino RTOS by allowing local users to bypass normal access controls and execute arbitrary code with the privileges of the target user or system processes. This vulnerability is particularly concerning in embedded systems and real-time environments where QNX Neutrino RTOS is commonly deployed, as these systems often handle critical infrastructure functions where unauthorized code execution could lead to significant operational disruptions or safety hazards. The vulnerability's local nature means that any user with access to the system can potentially exploit it, making it a serious concern for environments where multiple users share system resources or where physical access controls are insufficient.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security hardening measures. The most effective immediate solution involves applying the vendor-provided patches or updates that correct the buffer overflow conditions in the su and passwd commands through proper input validation and bounds checking mechanisms. Organizations should also implement additional security controls such as restricting access to these commands through file system permissions and implementing mandatory access controls that limit which users can execute privilege escalation utilities. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1068 which describes privilege escalation through the exploitation of system vulnerabilities, and T1548.003 which covers abuse of legitimate credentials for privilege escalation. System administrators should conduct thorough vulnerability assessments to identify all instances of the affected RTOS version and ensure that proper input validation is implemented across all command line utilities that process user-supplied arguments, particularly those that handle authentication and authorization functions.