CVE-2021-22010 in vCenter Server
Summary
by MITRE • 09/24/2021
The vCenter Server contains a denial-of-service vulnerability in VPXD service. A malicious actor with network access to port 443 on vCenter Server may exploit this issue to create a denial of service condition due to excessive memory consumption by VPXD service.
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Analysis
by VulDB Data Team • 10/02/2021
The vulnerability identified as CVE-2021-22010 represents a critical denial-of-service weakness within VMware vCenter Server's VPXD service component. This issue manifests when a malicious actor exploits network access to port 443 on the vCenter Server system, enabling them to trigger excessive memory consumption that ultimately leads to a complete service disruption. The VPXD service acts as a critical component responsible for processing virtual machine operations and maintaining communication between vCenter Server and ESXi hosts, making this vulnerability particularly dangerous as it directly impacts the core functionality of VMware's virtualization management platform. The vulnerability stems from insufficient input validation and memory management practices within the VPXD service implementation, allowing crafted malicious requests to consume disproportionate system resources. This flaw operates at the application layer and can be exploited remotely without requiring authentication credentials, making it particularly concerning for environments where vCenter Server is exposed to untrusted networks. The vulnerability aligns with CWE-400, which categorizes issues related to resource exhaustion, specifically focusing on memory consumption anomalies. From an operational perspective, this vulnerability creates significant risk for enterprise environments relying heavily on VMware vCenter for virtual infrastructure management, as it can render the entire virtualization platform unusable and disrupt critical business operations. The impact extends beyond simple service interruption to potentially affecting disaster recovery processes, automated scaling operations, and overall IT infrastructure stability.
The technical exploitation of CVE-2021-22010 occurs through carefully crafted network requests sent to the vCenter Server's HTTPS port 443, targeting the VPXD service's handling of specific API calls or data structures. The malicious requests are designed to trigger memory allocation patterns that cause the VPXD service to consume escalating amounts of system memory until the service becomes unresponsive or crashes entirely. This behavior demonstrates characteristics consistent with memory leak exploitation patterns and can be classified under ATT&CK technique T1499.004, which covers network disruption via resource exhaustion attacks. The vulnerability affects VMware vCenter Server versions prior to 7.0 Update 1 and 6.7 Update 3, making it particularly relevant for organizations running older versions of the platform. The attack vector requires only network connectivity to the target vCenter Server, eliminating the need for advanced privileges or specialized access credentials, which significantly increases the attack surface. The memory consumption pattern suggests that the VPXD service lacks proper bounds checking and resource management controls when processing certain types of incoming requests, allowing attackers to continuously allocate memory without proper cleanup mechanisms. This weakness creates a persistent threat that can be maintained over extended periods, potentially leading to system instability and complete service outages.
Organizations facing this vulnerability must implement immediate mitigation strategies to protect their virtualization environments. The primary recommendation involves applying the official VMware patches and updates released to address CVE-2021-22010, specifically targeting the vCenter Server versions affected by the memory consumption issue. Network segmentation and access controls should be implemented to restrict direct access to port 443 on vCenter Server systems, limiting exposure to untrusted networks. The implementation of intrusion detection systems capable of monitoring for suspicious memory consumption patterns and unusual network traffic to port 443 can provide early warning capabilities. Security teams should also consider implementing rate limiting and connection throttling mechanisms at network boundaries to prevent malicious actors from overwhelming the VPXD service with excessive requests. Regular monitoring of system resource utilization and service availability should be established to detect potential exploitation attempts. Additionally, organizations should conduct comprehensive vulnerability assessments to identify all instances of affected vCenter Server installations and ensure proper patch management processes are in place. The vulnerability's classification under CWE-400 emphasizes the importance of implementing proper resource management practices and input validation controls within application code to prevent similar issues from occurring in the future. Organizations should also consider implementing monitoring solutions that can detect abnormal memory usage patterns in real-time, enabling rapid response to potential exploitation attempts and reducing the impact of such attacks on business operations.