CVE-2021-1121 in vGPU Software
Summary
by MITRE • 10/30/2021
NVIDIA vGPU software contains a vulnerability in the Virtual GPU Manager kernel driver, where a vGPU can cause resource starvation among other vGPUs hosted on the same GPU, which may lead to denial of service.
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Analysis
by VulDB Data Team • 11/04/2021
The vulnerability identified as CVE-2021-1121 resides within NVIDIA's vGPU software ecosystem, specifically within the Virtual GPU Manager kernel driver component. This flaw represents a significant security concern for virtualized GPU environments where multiple virtual machines share physical GPU resources through vGPU technology. The vulnerability manifests as a resource starvation condition that can be exploited by a single vGPU to disrupt operations of other vGPUs operating on the same physical GPU device. The affected kernel driver operates at a privileged level within the system, making it a critical component for maintaining system stability and resource allocation across virtualized environments.
The technical implementation of this vulnerability stems from insufficient resource management and allocation controls within the Virtual GPU Manager driver. When a malicious or compromised vGPU instance attempts to consume excessive system resources, the kernel driver fails to properly enforce resource limits and isolation mechanisms. This allows one virtual GPU to monopolize GPU memory, compute units, or other critical resources, effectively starving other vGPUs that are simultaneously hosted on the same physical GPU. The flaw operates at the kernel level, meaning that standard user-space protections and monitoring mechanisms are insufficient to prevent or detect this resource exhaustion scenario. The vulnerability is particularly concerning because it can be triggered by a single compromised vGPU instance, potentially affecting the entire GPU allocation pool and causing cascading failures across multiple virtual machines.
The operational impact of CVE-2021-1121 extends beyond simple denial of service conditions, creating potential for widespread system instability and service disruption in virtualized data center environments. Organizations utilizing NVIDIA vGPU technology for cloud computing, virtual desktop infrastructure, or high-performance computing workloads face significant risk from this vulnerability. The resource starvation condition can lead to complete system crashes, application failures, and extended downtime for virtualized services. In enterprise environments, this vulnerability could compromise the reliability of critical applications that depend on GPU-accelerated virtualization, potentially resulting in financial losses and service level agreement violations. The vulnerability's exploitation does not require elevated privileges beyond what is normally available to a vGPU instance, making it particularly dangerous in multi-tenant environments where different users or applications share the same physical GPU hardware.
Mitigation strategies for CVE-2021-1121 should focus on both immediate patching and operational hardening measures. NVIDIA has released updates to address this vulnerability, and organizations must prioritize applying these patches to all affected systems. System administrators should implement monitoring solutions that track GPU resource utilization patterns and alert on abnormal consumption spikes that could indicate exploitation attempts. The implementation of resource quotas and limits at the vGPU level can provide additional protection by preventing any single virtual GPU from consuming excessive resources. Organizations should also consider implementing network segmentation and access controls to limit which entities can create or manage vGPU instances. From a compliance perspective, this vulnerability aligns with CWE-400 which addresses unchecked resource consumption, and could be mapped to ATT&CK technique T1499.001 for resource hijacking. The vulnerability underscores the importance of maintaining up-to-date security patches and implementing robust resource management policies in virtualized environments.