CVE-2023-20871 in Fusion
Summary
by MITRE • 04/26/2023
VMware Fusion contains a local privilege escalation vulnerability. A malicious actor with read/write access to the host operating system can elevate privileges to gain root access to the host operating system.
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Analysis
by VulDB Data Team • 09/01/2025
The vulnerability identified as CVE-2023-20871 resides within VMware Fusion, a virtualization platform designed for macOS environments. This critical local privilege escalation flaw represents a significant security weakness that allows attackers with basic read/write permissions on the host system to escalate their privileges to root level access. The vulnerability stems from insufficient access controls and privilege management mechanisms within the virtualization software's host operating system components. Attackers exploiting this vulnerability can leverage the compromised system to gain complete administrative control over the host macOS environment, effectively bypassing all standard security boundaries that typically protect against unauthorized access.
The technical implementation of this privilege escalation vulnerability involves exploiting weaknesses in how VMware Fusion manages system permissions and access controls during virtual machine operations. The flaw likely manifests through improper handling of system calls, insufficient validation of user privileges, or inadequate sandboxing mechanisms that should normally isolate virtualized processes from the underlying host system. According to CWE classification, this vulnerability aligns with CWE-276, which addresses improper privileges, and potentially CWE-732, concerning incorrect permissions for critical resources. The attack vector requires only local access with read/write capabilities, making it particularly dangerous as it can be exploited by adversaries who have already gained some foothold on the system through other means.
The operational impact of CVE-2023-20871 extends far beyond simple privilege escalation, as it fundamentally compromises the security architecture of macOS systems running VMware Fusion. Once an attacker achieves root access through this vulnerability, they can manipulate system files, install persistent backdoors, exfiltrate sensitive data, and disable security controls without detection. The vulnerability undermines the core security model of virtualization platforms, where the host operating system should maintain strict isolation from guest virtual machines and user processes. This weakness creates a potential pathway for attackers to move laterally within networks, escalate their operations, and maintain persistent access to compromised systems. The implications are particularly severe in enterprise environments where VMware Fusion is commonly used for development, testing, and virtualized application deployment.
Mitigation strategies for CVE-2023-20871 must address both immediate remediation and long-term security hardening measures. VMware has released patches and updates to resolve this vulnerability, which organizations should deploy immediately across all affected systems. System administrators should implement strict access controls and privilege management policies, ensuring that only authorized users have read/write access to host systems. The principle of least privilege should be enforced rigorously, with regular audits of system permissions and user access rights. Organizations should also consider implementing additional security controls such as endpoint detection and response solutions, file integrity monitoring, and network segmentation to limit the potential impact of successful exploitation. According to ATT&CK framework, this vulnerability maps to technique T1068, which covers local privilege escalation, and T1548, covering abuse of privilege, making it a critical target for defensive security measures. Regular security assessments and penetration testing should be conducted to identify and remediate similar vulnerabilities in virtualization environments.