CVE-2014-3633 in libvirt
Summary
by MITRE
The qemuDomainGetBlockIoTune function in qemu/qemu_driver.c in libvirt before 1.2.9, when a disk has been hot-plugged or removed from the live image, allows remote attackers to cause a denial of service (crash) or read sensitive heap information via a crafted blkiotune query, which triggers an out-of-bounds read.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 02/21/2022
The vulnerability described in CVE-2014-3633 represents a critical heap-based out-of-bounds read flaw within the libvirt virtualization management library, specifically affecting the qemuDomainGetBlockIoTune function. This issue exists in libvirt versions prior to 1.2.9 and manifests when dealing with dynamically managed virtual machine disk configurations where disks are hot-plugged or removed from live virtual machine images. The flaw stems from inadequate input validation and memory management within the block I/O tuning query processing mechanism, creating a pathway for remote attackers to exploit the system through crafted blkiotune queries.
The technical exploitation of this vulnerability occurs when libvirt processes block I/O tuning requests for virtual machine disks that have undergone dynamic changes during runtime. The qemuDomainGetBlockIoTune function fails to properly validate the state of disk objects that have been modified through hot-plug or removal operations, leading to memory access violations when attempting to read beyond allocated heap boundaries. This out-of-bounds read condition can result in unpredictable behavior including system crashes or information disclosure, as attackers can potentially extract sensitive heap data that may contain system memory contents or internal state information.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it enables remote attackers to potentially gain insights into the internal memory structure of the libvirt daemon. This information disclosure aspect poses significant security risks for virtualized environments where multiple tenants share the same hypervisor infrastructure, as attackers could potentially exploit the leaked memory information to conduct further attacks or bypass security controls. The vulnerability is particularly concerning in cloud computing environments where libvirt manages numerous virtual machines and where the attack surface is amplified by the complexity of dynamic disk management operations.
Mitigation strategies for CVE-2014-3633 primarily focus on upgrading to libvirt version 1.2.9 or later, which includes patches addressing the out-of-bounds read condition through improved input validation and memory management. System administrators should also implement network segmentation and access controls to limit exposure of libvirt management interfaces to untrusted networks. Additionally, monitoring for unusual patterns in block I/O tuning queries and implementing intrusion detection systems can help identify potential exploitation attempts. This vulnerability aligns with CWE-125 Out-of-bounds Read and can be classified under ATT&CK technique T1059 Command and Scripting Interpreter for privilege escalation and system compromise scenarios. Organizations should also consider implementing automated patch management processes to ensure timely remediation of similar vulnerabilities in virtualization management components, as this flaw demonstrates the critical importance of maintaining up-to-date virtualization infrastructure to prevent remote code execution and information disclosure attacks.