CVE-2015-5191 in vCenter Server
Summary
by MITRE
VMware Tools prior to 10.0.9 contains multiple file system races in libDeployPkg, related to the use of hard-coded paths under /tmp. Successful exploitation of this issue may result in a local privilege escalation.
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Analysis
by VulDB Data Team • 11/02/2019
The vulnerability identified as CVE-2015-5191 affects VMware Tools versions prior to 10.0.9 and represents a critical file system race condition within the libDeployPkg component. This flaw stems from the improper handling of temporary file operations during the deployment process, specifically utilizing hard-coded paths under the /tmp directory structure. The vulnerability resides in the fundamental design of how temporary files are created and managed during package deployment operations, creating exploitable conditions that can be leveraged by malicious actors.
The technical implementation of this vulnerability involves a classic race condition scenario where an attacker can manipulate the timing of file creation operations to replace legitimate temporary files with malicious counterparts. The use of hard-coded paths under /tmp creates predictable file locations that can be targeted through symbolic link attacks or direct file replacement techniques. When VMware Tools executes deployment operations, it creates temporary files in the /tmp directory without proper synchronization mechanisms or secure file creation practices, allowing attackers to exploit the window of opportunity between file existence checks and actual file operations.
From an operational impact perspective, this vulnerability enables local privilege escalation attacks that can potentially elevate an unprivileged user's privileges to that of the root user or system administrator. The attack vector requires local system access but does not necessitate network connectivity, making it particularly dangerous in environments where local access is possible. The privilege escalation occurs because the vulnerable code executes with elevated privileges during the deployment process, and the race condition allows attackers to inject malicious code into the temporary file locations. This vulnerability directly maps to CWE-367, which describes the Dangerous Use of tmp Directory, and represents a specific instance of improper file system permissions and race condition exploitation.
The exploitation of this vulnerability follows established attack patterns documented in the MITRE ATT&CK framework under techniques such as privilege escalation and local persistence. Attackers typically leverage the race condition by creating symbolic links or replacing temporary files with malicious payloads before the vulnerable code executes, thereby gaining elevated privileges. The impact extends beyond individual system compromise as successful exploitation can lead to complete system control, data exfiltration, and lateral movement within compromised networks. Organizations running affected VMware Tools versions face significant risk, particularly in virtualized environments where multiple users may have local access to virtual machines.
Mitigation strategies for this vulnerability include immediate upgrade to VMware Tools version 10.0.9 or later, which addresses the file system race condition through proper temporary file handling mechanisms. System administrators should also implement additional security controls such as restrictive permissions on /tmp directories, monitoring for suspicious file creation patterns, and regular vulnerability assessments of virtualized environments. The fix typically involves implementing proper file creation atomicity, using secure temporary file creation functions, and eliminating the use of hard-coded paths that can be easily targeted by attackers. Organizations should also consider implementing privilege separation mechanisms and monitoring for unauthorized access attempts to temporary file locations as part of their overall security posture.