CVE-2021-22018 in vCenter Server
Summary
by MITRE • 09/24/2021
The vCenter Server contains an arbitrary file deletion vulnerability in a VMware vSphere Life-cycle Manager plug-in. A malicious actor with network access to port 9087 on vCenter Server may exploit this issue to delete non critical files.
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Analysis
by VulDB Data Team • 10/02/2021
The vulnerability identified as CVE-2021-22018 represents a critical arbitrary file deletion flaw within VMware vCenter Server's vSphere Life-cycle Manager plug-in. This security weakness resides in the server's handling of file operations within the management interface, specifically affecting the lifecycle management capabilities of virtual environments. The vulnerability exists at the application level where proper input validation and access control mechanisms have been insufficiently implemented, allowing unauthorized deletion of files that should remain protected. The affected component operates on port 9087, which serves as a communication endpoint for the vSphere Life-cycle Manager functionality, making it a prime target for exploitation by malicious actors who gain network access to the vCenter Server infrastructure.
The technical exploitation of this vulnerability stems from inadequate sanitization of file path inputs within the plug-in's file deletion routines. Attackers can craft malicious requests that bypass normal file access controls and execute destructive operations against the target system. This flaw falls under the category of improper input validation as defined by CWE-20, where the system fails to properly validate or sanitize user-supplied data before processing it. The vulnerability allows for arbitrary file deletion because the system does not properly verify the legitimacy of file paths or enforce proper access controls during deletion operations. The exploitation requires network connectivity to the vCenter Server on port 9087, which represents a significant attack surface since this port is often exposed to external networks in enterprise environments. The vulnerability's classification aligns with ATT&CK technique T1485 which covers data destruction and the broader category of privilege escalation through improper access controls.
The operational impact of this vulnerability extends beyond simple file deletion capabilities, as it can potentially compromise the integrity and availability of virtual infrastructure management systems. While the vulnerability description indicates that only non-critical files can be deleted, the implications for system stability and operational continuity remain significant. An attacker could potentially disrupt vSphere Life-cycle Manager operations by deleting configuration files or other supporting components that maintain the integrity of virtual environment management. The attack surface is particularly concerning in enterprise environments where vCenter Server serves as the central management point for large-scale virtual infrastructures. Organizations may experience service degradation or complete disruption of lifecycle management capabilities, leading to operational challenges in maintaining virtual machine configurations and software updates. The vulnerability could also serve as a stepping stone for more sophisticated attacks, as the successful exploitation demonstrates the presence of insufficient access controls within the vCenter Server environment. This weakness may enable attackers to gain deeper insights into the system's architecture and potentially identify additional vulnerabilities within the broader vSphere ecosystem, making it a valuable target for reconnaissance and further exploitation activities.
Mitigation strategies for CVE-2021-22018 should focus on immediate patching of affected vCenter Server installations to address the underlying input validation flaws in the vSphere Life-cycle Manager plug-in. Organizations must ensure that all systems are updated to the latest VMware releases that contain the necessary security fixes for this vulnerability. Network segmentation and access control measures should be implemented to restrict access to port 9087, limiting exposure to only authorized personnel and systems. The principle of least privilege should be enforced when configuring vCenter Server access controls, ensuring that only necessary users and applications have access to the affected functionality. Regular security audits and vulnerability assessments should be conducted to identify potential weaknesses in the vCenter Server configuration and ensure that proper access controls are maintained. Additionally, monitoring solutions should be deployed to detect anomalous file deletion activities or unauthorized access attempts to the vCenter Server management interface, providing early warning capabilities for potential exploitation attempts. Organizations should also implement network access controls and firewall rules that restrict access to the vCenter Server's management ports to trusted network segments only, reducing the attack surface and limiting the potential impact of successful exploitation attempts.