Source: cve@mitre.org
Untrusted search path vulnerability in the crttrap command in QNX Neutrino RTOS 6.2.1 allows local users to load arbitrary libraries via a LD_LIBRARY_PATH environment variable that references a malicious library.
QNX Neutrino RTOS 6.2.1 is vulnerable to a local privilege escalation due to an untrusted search path vulnerability in the crttrap command. This allows attackers to inject and execute arbitrary code by manipulating the LD_LIBRARY_PATH environment variable, potentially leading to system compromise and unauthorized access. The vulnerability is relatively old but could still be a threat in legacy systems.
Step 1: Environment Variable Manipulation: The attacker sets the LD_LIBRARY_PATH environment variable to point to a directory they control. This directory will contain a malicious shared library (e.g., libfoo.so) that is designed to be loaded by crttrap.
Step 2: Malicious Library Creation: The attacker crafts a malicious shared library with the same name as a library that crttrap attempts to load. This library contains the attacker's payload (e.g., code to escalate privileges or execute arbitrary commands).
Step 3: Triggering crttrap: The attacker executes the crttrap command. This can be done directly or indirectly, depending on how the system is configured.
Step 4: Library Loading: The crttrap command attempts to load a shared library. Due to the manipulated LD_LIBRARY_PATH, it loads the attacker's malicious library instead of the legitimate one.
Step 5: Code Execution: The attacker's payload within the malicious library is executed, potentially granting the attacker elevated privileges or allowing them to execute arbitrary commands.
The root cause lies in the crttrap command's failure to properly sanitize or control the search path used for loading shared libraries. Specifically, it uses the LD_LIBRARY_PATH environment variable to locate libraries. An attacker can set this variable to point to a directory containing a malicious shared library with the same name as a library the crttrap command attempts to load. When crttrap is executed, it will load the attacker-controlled library instead of the legitimate one, leading to code execution. The flaw is a lack of input validation and a failure to use a secure search path, allowing for arbitrary code execution within the context of the crttrap command's privileges.
This vulnerability is not directly associated with any specific APT group or known malware campaigns. However, it could be exploited by any attacker with local access to a vulnerable system. The age of the vulnerability makes it a potential target for opportunistic attacks. CISA KEV status: Not Listed
Monitor system logs for unusual activity related to the crttrap command.
Analyze process execution logs for the crttrap command and any associated library loading events.
Check for modifications to the LD_LIBRARY_PATH environment variable, especially if it's set to a non-standard location.
Implement file integrity monitoring to detect changes to system libraries and the crttrap executable.
Network monitoring for any unusual outbound connections originating from the compromised system after the exploit.
Upgrade to a patched version of QNX Neutrino RTOS 6.2.1 or later that addresses the vulnerability. If upgrading is not possible, apply vendor-provided patches.
Restrict the use of the LD_LIBRARY_PATH environment variable. Consider removing it entirely if not required.
Implement a secure search path mechanism within the crttrap command to prevent loading libraries from untrusted locations.
Review and harden the system's security configuration, including access controls and privilege separation.
Regularly scan the system for known vulnerabilities and apply security updates promptly.
Implement a robust patch management process to ensure that security updates are applied in a timely manner.