CVE-2021-22013 in vCenter Server
Summary
by MITRE • 09/24/2021
The vCenter Server contains a file path traversal vulnerability leading to information disclosure in the appliance management API. A malicious actor with network access to port 443 on vCenter Server may exploit this issue to gain access to sensitive information.
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Analysis
by VulDB Data Team • 10/02/2021
The vulnerability identified as CVE-2021-22013 represents a critical file path traversal weakness within VMware vCenter Server's appliance management API. This flaw exists in the server's handling of file paths during API requests, creating an exploitable condition that allows unauthorized access to sensitive system information. The vulnerability specifically affects the appliance management interface which operates on the standard HTTPS port 443, making it accessible to any attacker with network connectivity to the vCenter Server instance. The issue stems from inadequate input validation and sanitization of file path parameters within the API endpoints, enabling attackers to manipulate path resolution mechanisms to access files outside of the intended directory structure.
The technical implementation of this vulnerability allows an attacker to exploit the path traversal mechanism through carefully crafted API requests that manipulate directory navigation sequences such as ../ or ..\ in file path parameters. When the vCenter Server processes these malformed paths, it fails to properly validate or sanitize the input, resulting in the system resolving paths that should be restricted. This flaw enables access to sensitive configuration files, log data, and potentially system credentials that are stored in directories accessible through the API interface. The vulnerability is particularly concerning because it operates at the application layer and requires minimal privileges to exploit, as network access to port 443 is sufficient for initial exploitation.
The operational impact of CVE-2021-22013 extends beyond simple information disclosure, as the exposed data may include system configuration details, user credentials, and other sensitive artifacts that could facilitate further attacks within the virtualized environment. Attackers could potentially leverage this information to conduct privilege escalation attacks, identify other vulnerable systems within the network, or establish persistent access points. The vulnerability affects VMware vCenter Server appliances that are configured to expose the management API, making it a significant concern for organizations that rely on VMware's virtualization platform for their infrastructure. This weakness creates opportunities for attackers to gain comprehensive understanding of the target environment's configuration and security posture, which could be used to plan more sophisticated attacks.
Organizations should implement immediate mitigations including applying the latest security patches provided by VMware, which address the input validation issues in the appliance management API. Network segmentation and access controls should be strengthened to limit exposure of port 443 to trusted networks only, while monitoring for suspicious API access patterns should be enabled. The vulnerability aligns with CWE-22 Path Traversal and can be categorized under ATT&CK technique T1083 File and Directory Discovery, making it a significant threat vector for adversaries seeking to gather intelligence about virtualized environments. Additional defensive measures include implementing web application firewalls to filter malicious path traversal attempts and conducting regular security assessments of the vCenter Server configuration to identify potential exposure points.