CVE-2021-22015 in vCenter Server Appliance
Summary
by MITRE • 09/24/2021
The vCenter Server contains multiple local privilege escalation vulnerabilities due to improper permissions of files and directories. An authenticated local user with non-administrative privilege may exploit these issues to elevate their privileges to root on vCenter Server Appliance.
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Analysis
by VulDB Data Team • 10/02/2021
The vulnerability identified as CVE-2021-22015 represents a critical local privilege escalation issue within VMware vCenter Server Appliance environments. This flaw stems from inadequate permission controls on critical system files and directories, creating exploitable pathways for authenticated users to gain elevated privileges. The vulnerability specifically affects the vCenter Server Appliance implementation, which serves as the central management platform for VMware vSphere environments and handles critical infrastructure operations.
The technical nature of this vulnerability aligns with CWE-276, which addresses improper file permissions and inadequate access control mechanisms. The flaw manifests through insufficiently restrictive file and directory permissions that allow non-administrative users to access or modify system-critical components. Attackers can exploit these misconfigurations to escalate their privileges from standard user level to root access, effectively compromising the entire vCenter Server appliance. This represents a significant security gap since the vCenter Server typically operates with elevated privileges to manage virtual infrastructure, making it a prime target for privilege escalation attacks.
The operational impact of CVE-2021-22015 extends beyond simple privilege elevation, as it provides attackers with complete control over the vCenter Server appliance and subsequently the entire virtualized infrastructure it manages. Once escalated to root privileges, an attacker can modify system configurations, access sensitive data, manipulate virtual machine operations, and potentially establish persistent access within the environment. This vulnerability directly maps to ATT&CK technique T1068, which covers local privilege escalation, and can be leveraged as part of broader attack chains targeting virtualization environments. The implications are particularly severe in enterprise environments where vCenter Server serves as the central management point for critical business applications and infrastructure components.
Mitigation strategies for CVE-2021-22015 should prioritize immediate patching of affected vCenter Server Appliance versions through official VMware updates. Organizations must also implement comprehensive permission auditing to identify and correct improper file and directory access controls. System hardening practices should include regular security configuration reviews, implementation of principle of least privilege access controls, and monitoring for unauthorized privilege escalation attempts. Network segmentation and additional authentication controls can provide defense-in-depth measures to limit potential exploitation. The vulnerability demonstrates the critical importance of proper access control implementation and regular security assessments in virtualization management platforms, as these systems often serve as primary attack vectors for sophisticated adversaries targeting enterprise infrastructure.