CVE-2007-4591 in Workstation
Summary
by MITRE
vstor-ws60.sys in VMWare Workstation 6.0 allows local users to cause a denial of service (host operating system crash) and possibly gain privileges by sending a small file buffer size value to the FsSetVolumeInformation IOCTL handler with an FsSetFileInformation subcode.
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Analysis
by VulDB Data Team • 07/25/2019
The vulnerability described in CVE-2007-4591 represents a critical security flaw in VMware Workstation 6.0's virtual device driver vstor-ws60.sys which operates at the kernel level within the host operating system. This issue manifests through improper input validation within the FsSetVolumeInformation IOCTL handler, specifically when processing FsSetFileInformation subcode requests. The vulnerability exists in the virtual storage device driver that manages file system operations between the guest operating system and the host storage layer, creating a potential attack surface where malicious input can disrupt normal system operations.
The technical implementation of this flaw involves a buffer size parameter that is not adequately validated before being processed by the kernel-mode driver. When a local attacker sends a specially crafted file buffer size value that is smaller than expected, the driver fails to properly handle this malformed input, leading to memory corruption within the kernel space. This memory corruption typically results in a kernel crash or system hang, manifesting as a denial of service condition that can bring the entire host operating system to a halt. The vulnerability's exploitation path begins with local user access to the system, as the attack requires execution within the context of the host operating system where the vulnerable driver is loaded.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enabling privilege escalation under certain conditions. When the buffer overflow occurs in kernel space, it can be exploited to execute arbitrary code with the highest system privileges, allowing attackers to gain root or administrator access to the host system. This represents a significant escalation from a simple DoS condition to a full system compromise, as the compromised host can then be used as a launching point for further attacks against networked resources or to maintain persistent access. The vulnerability affects the integrity and availability of the entire virtualization environment, potentially compromising multiple virtual machines running on the same host.
Mitigation strategies for this vulnerability should focus on immediate patch application from VMware, which addressed the issue through proper input validation and buffer size checking within the affected driver component. System administrators should implement the latest VMware Workstation updates and ensure that all virtualization environments are running patched versions. Additionally, monitoring for unusual system crashes or kernel panics can help identify potential exploitation attempts. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and maps to ATT&CK technique T1059 for privilege escalation through kernel-mode exploitation. Network segmentation and access controls should be implemented to limit local user access to systems running vulnerable virtualization software, while regular security audits should verify that all virtualization components are properly updated and maintained to prevent exploitation of similar vulnerabilities in the future.