CVE-2014-0476 in chkrootkit
Summary
by MITRE
The slapper function in chkrootkit before 0.50 does not properly quote file paths, which allows local users to execute arbitrary code via a Trojan horse executable. NOTE: this is only a vulnerability when /tmp is not mounted with the noexec option.
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Analysis
by VulDB Data Team • 12/21/2024
The vulnerability identified as CVE-2014-0476 resides within the chkrootkit utility, specifically in the slapper function of versions prior to 0.50. This flaw represents a classic command injection vulnerability that exploits improper handling of file paths during system security checks. The vulnerability occurs when chkrootkit attempts to execute a Trojan horse detection mechanism that involves scanning temporary directories for suspicious executables. The core technical issue stems from inadequate shell argument quoting within the slapper function, which fails to properly sanitize file paths before incorporating them into system commands.
The operational impact of this vulnerability is significant for systems running vulnerable versions of chkrootkit, particularly when the /tmp filesystem is mounted without the noexec option. This configuration creates a dangerous environment where local attackers can place malicious executables in /tmp that will be executed by chkrootkit during its routine scanning operations. The vulnerability allows for arbitrary code execution with the privileges of the user running chkrootkit, which typically operates with elevated permissions during security scans. This represents a privilege escalation vector that can be exploited by malicious actors to gain unauthorized access to systems.
The flaw aligns with CWE-78, which describes improper neutralization of special elements used in shell commands, and demonstrates how command injection vulnerabilities can be leveraged in security tools themselves. This vulnerability also maps to ATT&CK technique T1059.007 for Command and Scripting Interpreter: Unix Shell, as it exploits shell execution through improper input handling. The security implications extend beyond simple code execution to include potential persistence mechanisms, as attackers can place malicious binaries that will be executed during subsequent chkrootkit runs. The vulnerability particularly affects systems where chkrootkit is run regularly as part of automated security monitoring processes, creating a persistent threat vector.
Mitigation strategies for CVE-2014-0476 require immediate patching of chkrootkit to version 0.50 or later, which addresses the improper quoting issue in the slapper function. Additionally, system administrators should ensure that the /tmp filesystem is mounted with the noexec option to prevent execution of binaries from temporary directories. This additional layer of protection provides defense in depth against similar vulnerabilities and aligns with security best practices for temporary file handling. Organizations should also consider implementing proper file system permissions and monitoring for unauthorized changes to security tools, as the vulnerability requires local access to place malicious executables in the targeted directory. Regular security audits and vulnerability assessments should include checking for outdated security tools that may contain similar command injection flaws.