CVE-2012-6136 in tuned
Summary
by MITRE
tuned 2.10.0 creates its PID file with insecure permissions which allows local users to kill arbitrary processes.
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Analysis
by VulDB Data Team • 11/21/2019
The vulnerability identified as CVE-2012-6136 affects the tuned daemon version 2.10.0, which is a system tuning daemon used to optimize system performance based on workload profiles. This daemon is commonly deployed in enterprise environments to manage system configuration parameters dynamically. The flaw manifests in how the daemon handles its PID file creation process, which represents a classic privilege escalation and process manipulation vulnerability. The issue occurs during the daemon's initialization phase when it creates a PID file without properly setting restrictive file permissions.
The technical implementation of this vulnerability stems from the insecure creation of the PID file, which typically contains the process identifier of the running tuned daemon. When the daemon creates this file without setting appropriate permissions, it allows any local user on the system to read the PID value and subsequently attempt to send signals to that process. This behavior directly violates the principle of least privilege and creates an attack surface where unauthorized users can manipulate system processes. The insecure permissions typically mean the PID file is created with world-readable and world-writable permissions, or at minimum lacks proper ownership controls that would prevent unauthorized access.
The operational impact of this vulnerability is significant as it enables local privilege escalation attacks and process disruption. An attacker with local access can leverage this flaw to kill arbitrary processes, including potentially critical system services or other user processes. This capability can be exploited to cause denial of service conditions, disrupt legitimate system operations, or even escalate privileges by killing processes that might be running with elevated permissions. The vulnerability essentially provides a mechanism for process termination attacks that bypass normal access controls, making it particularly dangerous in multi-user environments where different users might have varying levels of system access.
From a cybersecurity perspective, this vulnerability aligns with CWE-732, which describes improper permission assignment, and represents a clear violation of the principle of least privilege. The attack vector falls under the MITRE ATT&CK framework category of Privilege Escalation and Defense Evasion techniques, specifically targeting process manipulation and system service disruption. The vulnerability demonstrates poor secure coding practices in file permission management and highlights the importance of proper access control mechanisms in system-level daemons. Organizations should implement immediate mitigations including updating to patched versions of the tuned daemon, manually correcting PID file permissions, and conducting comprehensive audits of other system services for similar permission-related vulnerabilities. Additionally, system administrators should review and implement proper monitoring for unauthorized process termination activities and ensure that daemon processes properly enforce access controls through appropriate file permissions and ownership settings.