CVE-2014-3689 in QEMU
Summary
by MITRE
The vmware-vga driver (hw/display/vmware_vga.c) in QEMU allows local guest users to write to qemu memory locations and gain privileges via unspecified parameters related to rectangle handling.
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Analysis
by VulDB Data Team • 02/24/2022
The vulnerability identified as CVE-2014-3689 resides within the VMware VGA driver implementation in QEMU virtualization software, specifically in the hw/display/vmware_vga.c file. This flaw represents a critical privilege escalation vector that enables local guest users to manipulate memory locations within the QEMU process, potentially leading to complete system compromise. The vulnerability manifests during rectangle handling operations, which are fundamental graphics operations used in virtualized environments to render display content. The unspecified parameters mentioned in the description suggest that the driver fails to properly validate or sanitize input parameters related to graphics operations, creating a pathway for malicious memory manipulation.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-787, which covers out-of-bounds write operations. The flaw occurs because the VMware VGA driver does not adequately validate the parameters passed during rectangle drawing operations, allowing a malicious guest user to craft specific input that results in unauthorized memory writes within the QEMU process space. This type of vulnerability falls under the ATT&CK technique T1055.011, specifically process injection via direct memory manipulation, where an attacker can modify memory locations to execute arbitrary code with elevated privileges. The vulnerability exploits the trust relationship between the guest operating system and the hypervisor, allowing guest users to bypass normal security boundaries.
The operational impact of this vulnerability is severe as it enables local privilege escalation from guest user level to QEMU process level, which typically runs with elevated privileges. An attacker who gains access to a guest virtual machine can leverage this vulnerability to execute arbitrary code within the host system, potentially compromising the entire virtualization environment. This creates a multi-tenant security risk where one compromised guest can affect other guests running on the same hypervisor, leading to lateral movement and potential data breaches across multiple virtual machines. The vulnerability affects QEMU versions prior to 2.1.0, making it particularly dangerous in environments where virtualization software is not regularly updated.
Mitigation strategies for CVE-2014-3689 include immediate patching of QEMU to version 2.1.0 or later, where the vulnerability has been addressed through proper parameter validation in the VMware VGA driver. Organizations should implement regular virtualization software updates as part of their security maintenance procedures, particularly for hypervisor components that handle guest input processing. Additional protective measures include implementing strict access controls within virtual environments, monitoring for unusual memory access patterns, and employing hypervisor-level security features such as Intel VT-d or AMD-Vi for device assignment and memory protection. Network segmentation and isolation of virtual environments can also limit the potential impact if a guest system is compromised. The vulnerability highlights the importance of input validation in hypervisor drivers and demonstrates how graphics-related components can serve as attack vectors for privilege escalation, emphasizing the need for comprehensive security testing of all hypervisor components including display drivers and device emulators.