CVE-2014-4947 in XenServer
Summary
by MITRE
Buffer overflow in the HVM graphics console support in Citrix XenServer 6.2 Service Pack 1 and earlier has unspecified impact and attack vectors.
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Analysis
by VulDB Data Team • 02/09/2022
The vulnerability identified as CVE-2014-4947 represents a critical buffer overflow condition within the Hardware Virtual Machine graphics console support functionality of Citrix XenServer versions 6.2 Service Pack 1 and earlier. This flaw exists in the hypervisor layer where guest operating systems interact with virtualized graphics hardware through the HVM console interface. The buffer overflow occurs when processing graphics console data, specifically during the handling of malformed or excessively large input payloads that exceed the allocated buffer boundaries. Such vulnerabilities in hypervisor components are particularly dangerous because they can potentially allow attackers to execute arbitrary code at the host level, bypassing traditional virtualization security boundaries.
The technical implementation of this vulnerability stems from inadequate input validation and memory management within the graphics console driver code. When a guest operating system sends graphics console data to the hypervisor, the system fails to properly validate the size and content of incoming buffers before copying them into fixed-size memory regions. This classic buffer overflow condition creates opportunities for attackers to overwrite adjacent memory locations, potentially corrupting critical data structures or injecting malicious code that executes with the privileges of the hypervisor process. The unspecified impact and attack vectors indicate that the vulnerability could be exploited through multiple pathways including guest-to-host communication channels, remote network access, or local privilege escalation scenarios.
The operational impact of this vulnerability extends far beyond individual virtual machine compromise, as it fundamentally undermines the security isolation that virtualization environments are designed to provide. An attacker who successfully exploits this buffer overflow could gain complete control over the host system, potentially leading to data breaches, service disruption, or further lateral movement within the virtualized infrastructure. The implications are particularly severe for cloud environments and data centers where multiple tenants share the same physical hardware, as this vulnerability could enable one compromised guest to attack other guests or the underlying host infrastructure. Organizations running affected XenServer versions face significant risk of unauthorized access to their entire virtualized environment, potentially compromising thousands of virtual machines simultaneously.
Mitigation strategies for CVE-2014-4947 should prioritize immediate patching of affected Citrix XenServer installations to the latest service pack versions that contain the necessary security fixes. Organizations should implement network segmentation and access controls to limit exposure of virtualization infrastructure to untrusted networks while monitoring for suspicious activity patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and represents a potential entry point for ATT&CK techniques involving privilege escalation and persistence within virtualized environments. Regular security assessments of virtualization infrastructure should include thorough testing of hypervisor components and monitoring for anomalous behavior in graphics console communications. System administrators should also consider implementing hypervisor-level security controls and maintaining detailed audit logs of all virtual machine console interactions to facilitate incident response and forensic analysis in case of exploitation attempts.