CVE-2015-0237 in Enterprise Virtualization Manager
Summary
by MITRE
Red Hat Enterprise Virtualization (RHEV) Manager before 3.5.1 ignores the permission to deny snapshot creation during live storage migration between domains, which allows remote authenticated users to cause a denial of service (prevent host start) by creating a long snapshot chain.
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Analysis
by VulDB Data Team • 05/10/2022
The vulnerability identified as CVE-2015-0237 represents a critical access control flaw within Red Hat Enterprise Virtualization Manager versions prior to 3.5.1. This issue stems from improper permission validation during storage migration operations, specifically affecting the snapshot creation process when migrating virtual machines between different storage domains. The flaw exists in the authorization mechanisms that govern virtual machine management operations, creating a scenario where authenticated users can bypass expected security controls. The vulnerability manifests when users attempt to perform live storage migration while simultaneously creating snapshots, leading to an unexpected state that can severely impact system availability. This represents a fundamental breakdown in the principle of least privilege, where users who should not be able to create snapshots during migration operations are granted this capability through a logic error in the permission checking system. The vulnerability is particularly concerning as it operates within the core virtualization management infrastructure, where unauthorized actions can cascade into broader system impacts.
The technical implementation of this vulnerability involves a race condition and permission validation error within the RHEV Manager's storage migration subsystem. During live storage migration operations, the system should enforce strict controls preventing snapshot creation to maintain data consistency and prevent corruption. However, due to a flaw in the authorization logic, the system fails to properly validate whether the user has the appropriate permissions to create snapshots while migration is in progress. This oversight creates a pathway where authenticated users can manipulate the snapshot chain beyond normal operational limits, effectively creating a chain of snapshots that can grow indefinitely. The system's failure to properly enforce access controls during this specific operation allows users to submit snapshot creation requests that would normally be denied, leading to an accumulation of snapshot metadata that eventually causes the host to become unresponsive. The flaw essentially allows for a form of resource exhaustion attack where the system's internal state becomes corrupted through unauthorized snapshot operations. This vulnerability directly relates to CWE-285, which addresses improper authorization issues, and can be classified under the ATT&CK technique T1499.001 for Network Denial of Service, as the impact results in system unavailability.
The operational impact of CVE-2015-0237 extends beyond simple denial of service to potentially compromise entire virtualization environments. When users exploit this vulnerability, they can create extremely long snapshot chains that consume significant system resources and eventually prevent host startup operations. This scenario can lead to complete system outages where administrators cannot recover virtual machines or restart host services. The vulnerability affects the core functionality of RHEV Manager, making it impossible to maintain consistent virtual machine states and potentially leading to data corruption. The impact is particularly severe in production environments where virtualization platforms handle critical workloads, as the vulnerability can be exploited by malicious insiders or external attackers who have gained authenticated access to the system. The resource consumption from extended snapshot chains can also affect storage capacity and performance of the entire virtualization infrastructure. Additionally, the vulnerability can make automated recovery processes fail, as the system cannot properly handle the corrupted state caused by the excessive snapshot creation. This type of vulnerability undermines the fundamental security posture of virtualization environments and can result in extended downtime, service disruption, and potential data loss scenarios.
Organizations affected by CVE-2015-0237 should immediately implement the remediation measures provided by Red Hat, including upgrading to RHEV Manager version 3.5.1 or later where the vulnerability has been addressed. The upgrade process should include comprehensive testing to ensure that the updated system properly enforces snapshot creation permissions during storage migration operations. Network segmentation and access controls should be reviewed to limit the number of authenticated users with sufficient privileges to perform storage migration operations. Implementing monitoring solutions that can detect unusual snapshot creation patterns or excessive snapshot chain lengths can provide early warning of potential exploitation attempts. System administrators should also conduct regular audits of virtual machine configurations and storage migration activities to identify any anomalous behavior that might indicate exploitation. The vulnerability highlights the importance of proper access control implementation in virtualization management systems and underscores the need for regular security assessments of core infrastructure components. Organizations should consider implementing additional security controls such as mandatory access controls or enhanced logging mechanisms that can track and prevent unauthorized snapshot operations during critical system processes. Regular security training for administrators on virtualization security best practices can also help prevent exploitation through social engineering or insider threats. The remediation process should include comprehensive documentation of the vulnerability's impact and the steps taken to address it, ensuring that similar issues can be identified and resolved in other components of the virtualization infrastructure.