CVE-2013-4236 in Enterprise Virtualization
Summary
by MITRE
VDSM in Red Hat Enterprise Virtualization 3 and 3.2 allows privileged guest users to cause the host to become "unavailable to the managment server" via invalid XML characters in a guest agent response. NOTE: this issue is due to an incomplete fix for CVE-2013-0167.
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Analysis
by VulDB Data Team • 01/04/2022
The vulnerability identified as CVE-2013-4236 represents a critical security flaw in the Virtual Desktop Service Manager VDSM component of Red Hat Enterprise Virtualization versions 3 and 3.2. This issue specifically targets the communication channel between guest virtual machines and the host management server, creating a potential avenue for denial of service attacks that could severely impact virtualized environments. The vulnerability stems from inadequate input validation mechanisms within the guest agent response processing, where malformed XML data can be injected into the system.
The technical flaw manifests when privileged guest users execute malicious actions that introduce invalid XML characters into responses generated by the guest agent. This particular weakness falls under the CWE-20 category of "Improper Input Validation" and represents an incomplete remediation of the earlier CVE-2013-0167 vulnerability, indicating that the initial fix was insufficient to address all potential attack vectors. The root cause lies in the insufficient sanitization of XML data received from guest virtual machines, which allows specially crafted payloads to disrupt the normal communication flow between the guest agent and the host management server.
The operational impact of this vulnerability is significant as it can lead to complete unavailability of the host system from the management server perspective, effectively rendering the virtualized environment inaccessible to administrators. This disruption occurs because the malformed XML characters cause the host management server to fail in processing legitimate requests from the guest agent, resulting in a cascading failure that prevents proper system monitoring and control. Attackers can exploit this weakness to perform persistent denial of service attacks that systematically degrade the availability of critical virtualization infrastructure.
The vulnerability aligns with several ATT&CK techniques including T1499.004 for Network Denial of Service and T1070.004 for Indicator Removal on Host. Organizations utilizing Red Hat Enterprise Virtualization 3 and 3.2 should implement immediate mitigations including applying the latest security patches from Red Hat, implementing network segmentation to limit guest access privileges, and deploying monitoring solutions to detect anomalous XML traffic patterns. Additionally, administrators should consider implementing strict XML parsing rules and input validation mechanisms within the VDSM configuration to prevent similar vulnerabilities from being exploited in the future. The incomplete nature of the previous fix highlights the importance of thorough vulnerability assessment and comprehensive remediation strategies to prevent such issues from persisting in security implementations.