CVE-2016-4444 in setroubleshoot
Summary
by MITRE
The allow_execmod plugin for setroubleshoot before 3.2.23 allows local users to execute arbitrary commands by triggering an execmod SELinux denial with a crafted binary filename, related to the commands.getstatusoutput function.
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Analysis
by VulDB Data Team • 11/28/2022
The CVE-2016-4444 vulnerability resides within the allow_execmod plugin component of setroubleshoot software versions prior to 3.2.23, presenting a critical security flaw that enables local privilege escalation through malicious command execution. This vulnerability specifically targets the handling of SELinux denials and exploits a design weakness in how the system processes certain binary filenames during security policy enforcement. The issue manifests when a local attacker crafts a malicious binary filename that triggers an execmod SELinux denial, subsequently allowing arbitrary command execution through the commands.getstatusoutput function. This represents a direct violation of the principle of least privilege and demonstrates a failure in proper input validation and sanitization within the security monitoring framework.
The technical exploitation of this vulnerability occurs through a specific code path that involves the commands.getstatusoutput function, which is commonly used for executing shell commands and capturing their output. When the allow_execmod plugin encounters a crafted binary filename that generates an execmod SELinux denial, the system's response mechanism fails to properly sanitize or validate the input before passing it to the command execution function. This creates an arbitrary code execution vector where attackers can inject malicious commands through seemingly benign filenames that are processed by the security monitoring system itself. The vulnerability essentially transforms a security monitoring tool into an attack surface that can be leveraged by local users to bypass security controls and execute unauthorized operations with elevated privileges.
The operational impact of CVE-2016-4444 extends beyond simple local privilege escalation, as it represents a fundamental flaw in the security architecture of SELinux policy enforcement mechanisms. This vulnerability allows attackers to bypass mandatory access controls that are specifically designed to prevent unauthorized command execution, effectively undermining the core security model of SELinux. The implications are particularly severe in environments where setroubleshoot is actively monitoring security policies, as it enables attackers to execute arbitrary commands with the privileges of the monitoring process. This vulnerability also aligns with attack patterns documented in the MITRE ATT&CK framework under techniques related to privilege escalation and execution through system components, specifically targeting the use of legitimate system tools for malicious purposes.
From a compliance and security standards perspective, this vulnerability directly relates to CWE-78 and CWE-88, which address command injection and argument injection flaws respectively. The weakness demonstrates poor input validation practices and improper handling of user-supplied data within security monitoring tools, creating a dangerous intersection between system monitoring and execution capabilities. Organizations implementing SELinux policies and using setroubleshoot for security monitoring face significant risk from this vulnerability, as it allows attackers to leverage legitimate security tool functionality for unauthorized access. The remediation strategy involves updating to setroubleshoot version 3.2.23 or later, which includes proper input sanitization and validation mechanisms that prevent malicious filenames from triggering unauthorized command execution through the commands.getstatusoutput function.
The broader implications of this vulnerability highlight the critical importance of input validation in security tooling and demonstrate how monitoring and enforcement mechanisms can themselves become attack vectors when not properly secured. This issue underscores the need for comprehensive security testing of security tools and emphasizes that even defensive mechanisms can contain exploitable flaws. The vulnerability also illustrates the complexity of modern security architectures where multiple layers of protection must work together without creating new attack surfaces, particularly in systems that combine policy enforcement with automated response mechanisms. Proper patch management and security monitoring of security tools themselves represent essential practices to prevent exploitation of vulnerabilities like CVE-2016-4444.