CVE-2014-8333 in Compute
Summary
by MITRE
The VMware driver in OpenStack Compute (Nova) before 2014.1.4 allows remote authenticated users to cause a denial of service (disk consumption) by deleting an instance in the resize state.
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Analysis
by VulDB Data Team • 04/03/2022
The vulnerability identified as CVE-2014-8333 resides within the VMware driver component of OpenStack Compute (Nova) and represents a significant denial of service weakness that affects systems running versions prior to 2014.1.4. This flaw specifically targets the handling of instance deletion operations when instances are in a resize state, creating a condition where malicious authenticated users can exploit the system to consume excessive disk resources. The vulnerability operates through a carefully orchestrated sequence of actions that leverages the interaction between the Nova compute service and VMware virtualization infrastructure, making it particularly dangerous in cloud environments where resource management is critical for service delivery and operational efficiency.
The technical implementation of this vulnerability stems from insufficient validation and resource cleanup mechanisms within the Nova driver's handling of resize operations. When an instance enters the resize state, the system prepares for a potential migration or scaling operation while maintaining references to temporary storage resources. However, the flaw occurs during the deletion process when the system fails to properly account for and release all associated disk resources that were allocated during the resize operation. This creates a resource leak scenario where temporary files and storage allocations persist in the system, gradually consuming available disk space. The vulnerability is classified under CWE-400 as an Uncontrolled Resource Consumption weakness, specifically manifesting as a denial of service condition that can be triggered remotely by authenticated users who understand the system's internal state management mechanisms.
The operational impact of CVE-2014-8333 extends beyond simple resource exhaustion to potentially compromise entire cloud environments and service availability. In production OpenStack deployments, this vulnerability can lead to cascading failures where disk space exhaustion causes the compute nodes to become unresponsive, preventing new instance creation or migration operations. The attack vector requires only authenticated access to the Nova API, which means that any user with valid credentials can exploit this weakness, making it particularly dangerous in multi-tenant environments where privilege escalation or credential compromise scenarios are possible. The vulnerability directly violates cloud security principles by allowing authenticated users to consume resources beyond their allocated quotas, potentially leading to service degradation for other tenants and creating opportunities for further exploitation through resource exhaustion attacks.
Mitigation strategies for CVE-2014-8333 primarily focus on immediate version upgrades to OpenStack Nova 2014.1.4 or later, which contain the necessary patches to properly handle resource cleanup during resize state deletion operations. System administrators should also implement monitoring solutions that track disk usage patterns and alert on unusual resource consumption spikes that might indicate exploitation attempts. The patch addresses the root cause by ensuring proper resource accounting and cleanup procedures during instance deletion, particularly when instances are in intermediate states such as resize. Additionally, implementing strict access controls and privilege management can help reduce the attack surface, as this vulnerability requires authenticated access to the system. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving resource exhaustion and denial of service, and should be considered in threat modeling exercises for cloud infrastructure environments. Organizations should also conduct regular vulnerability assessments and maintain updated security configurations to prevent exploitation of similar weaknesses in other components of their cloud infrastructure stack.