CVE-2024-6519 in QEMU
Summary
by MITRE • 10/21/2024
A use-after-free vulnerability was found in the QEMU LSI53C895A SCSI Host Bus Adapter emulation. This issue can lead to a crash or VM escape.
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Analysis
by VulDB Data Team • 08/08/2025
The CVE-2024-6519 vulnerability represents a critical use-after-free flaw within QEMU's emulation of the LSI53C895A SCSI Host Bus Adapter component. This vulnerability exists in virtualization environments where QEMU serves as the hypervisor platform for emulating hardware components, creating a potential pathway for malicious actors to exploit the underlying system architecture. The LSI53C895A SCSI controller is a widely used hardware component in virtualized environments, making this vulnerability particularly concerning for cloud providers and enterprise virtualization deployments.
The technical root cause of this vulnerability stems from improper memory management within the QEMU emulation layer. When the virtualized SCSI controller handles certain I/O operations, it fails to properly validate memory references after objects have been freed from memory. This use-after-free condition occurs during the processing of SCSI command sequences where the emulation code attempts to access memory locations that have already been deallocated. The flaw manifests when multiple SCSI operations are processed concurrently, leading to race conditions that allow memory corruption to occur. This type of vulnerability falls under CWE-416 which specifically addresses use-after-free conditions, and represents a classic example of memory safety issues in virtualization software.
The operational impact of CVE-2024-6519 extends beyond simple system crashes, presenting a significant risk for virtual machine escape attacks that could compromise the entire host system. An attacker who successfully exploits this vulnerability could potentially execute arbitrary code within the host operating system, effectively breaking out of the isolated virtual machine environment. This VM escape capability aligns with ATT&CK technique T1068 which covers local privilege escalation through exploitation of software vulnerabilities. The vulnerability's impact is particularly severe in multi-tenant cloud environments where a single compromised virtual machine could potentially be used to attack other VMs running on the same host, creating a cascading security risk.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected QEMU installations, as vendors have released updated versions that address the memory management issues in the SCSI controller emulation. Organizations should implement network segmentation and access controls to limit potential exploitation vectors, while also monitoring for unusual system behavior that might indicate exploitation attempts. The fix typically involves implementing proper reference counting mechanisms and ensuring that all memory accesses occur only on valid, allocated memory regions. Additionally, virtualization administrators should consider implementing hypervisor-level security controls such as Intel VT-d or AMD-Vi to limit direct memory access capabilities of virtual machines, reducing the potential impact of successful exploitation attempts.