CVE-2014-4199 in Support Tools
Summary
by MITRE
vm-support 0.88 in VMware Tools, as distributed with VMware Workstation through 10.0.3 and other products, allows local users to write to arbitrary files via a symlink attack on a file in /tmp.
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Analysis
by VulDB Data Team • 07/04/2017
The vulnerability identified as CVE-2014-4199 represents a critical privilege escalation flaw within VMware Tools version 0.88, specifically affecting VMware Workstation versions up to 10.0.3 and other related products. This issue stems from inadequate file handling mechanisms within the vm-support utility that processes temporary files in the /tmp directory. The vulnerability manifests when local attackers exploit a race condition or symbolic link attack to manipulate file creation processes, enabling them to write arbitrary data to files outside the intended scope of the application. The root cause lies in the improper validation of temporary file paths and the absence of proper file ownership checks during file operations.
The technical exploitation of this vulnerability occurs through a carefully crafted symlink attack against files stored in the /tmp directory, which is a common temporary storage location accessible to all users on Unix-like systems. Attackers can create symbolic links that point to sensitive system files or configuration files, then trigger the vm-support utility to write data to these locations. This technique leverages the predictable nature of temporary file naming conventions and the lack of atomic file creation mechanisms. The vulnerability falls under CWE-367, which specifically addresses Time-of-Check to Time-of-Use (TOCTOU) race conditions, and represents a classic example of insecure temporary file handling that has been documented in numerous security advisories.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can potentially allow attackers to modify critical system files, inject malicious code into running processes, or alter configuration settings that control system behavior. An attacker with local access can exploit this vulnerability to gain elevated privileges, potentially leading to complete system compromise. The attack vector is particularly concerning because it requires minimal privileges to initiate and can be executed by any local user, making it a significant concern for multi-user environments where security isolation is paramount. This vulnerability directly impacts the principle of least privilege and can undermine the security model of virtualized environments where VMware Workstation is deployed.
Mitigation strategies for CVE-2014-4199 should focus on immediate patching of affected VMware Workstation versions, with the release of VMware Tools 0.89 and subsequent updates addressing the underlying file handling issues. System administrators should implement proper file permissions and ownership controls for temporary directories, ensuring that files created in /tmp are properly secured against symbolic link attacks. The implementation of atomic file creation mechanisms and proper validation of file paths can prevent such vulnerabilities from being exploited. Organizations should also consider implementing monitoring solutions that detect unusual file creation patterns in temporary directories, as well as applying the principle of least privilege to limit access to sensitive system files. This vulnerability demonstrates the importance of secure coding practices and proper file handling mechanisms, aligning with ATT&CK technique T1068 which covers local privilege escalation and the broader category of privilege escalation techniques that leverage system weaknesses.