CVE-2019-12928 in QEMU
Summary
by MITRE
The QMP migrate command in QEMU version 4.0.0 and earlier is vulnerable to OS command injection, which allows the remote attacker to achieve code execution, denial of service, or information disclosure by sending a crafted QMP command to the listening server.
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Analysis
by VulDB Data Team • 03/06/2025
The vulnerability identified as CVE-2019-12928 represents a critical security flaw in QEMU's QMP (QEMU Machine Protocol) implementation that affects versions 4.0.0 and earlier. This issue stems from improper input validation within the migrate command functionality, creating a pathway for malicious actors to inject operating system commands through carefully crafted QMP protocol messages. The QMP protocol serves as the primary interface for managing QEMU virtual machines remotely, making this vulnerability particularly dangerous as it can be exploited over network connections where QEMU instances are exposed to untrusted users or networks.
The technical exploitation of this vulnerability occurs when a remote attacker sends a specially crafted QMP command containing malicious input to a QEMU instance listening on a network port. The migrate command in question fails to properly sanitize or escape user-supplied parameters before incorporating them into system calls or shell commands within the QEMU process. This lack of proper input validation creates an OS command injection vector where attacker-controlled data can be executed as shell commands with the privileges of the QEMU process. The vulnerability is classified as a CWE-78 Improper Neutralization of Special Elements used in an OS Command, which is a well-established category of injection flaws that have been consistently exploited in various software systems.
The operational impact of this vulnerability extends beyond simple code execution capabilities to encompass denial of service and information disclosure scenarios. Remote attackers can leverage this vulnerability to execute arbitrary commands on the host system running QEMU, potentially gaining access to sensitive data, escalating privileges, or disrupting services through resource exhaustion attacks. The severity is compounded by the fact that QEMU instances are often deployed in cloud environments, virtualization platforms, and containerized applications where they may run with elevated privileges, making successful exploitation particularly damaging. This vulnerability affects systems where QEMU is configured to accept remote QMP connections, which is common in virtualization environments, cloud computing platforms, and automated infrastructure management systems.
Mitigation strategies for CVE-2019-12928 primarily focus on immediate version updates and network security controls. Organizations should upgrade to QEMU versions 4.0.1 or later where this vulnerability has been addressed through proper input validation and sanitization of QMP command parameters. Network segmentation and access controls should be implemented to restrict direct network access to QEMU instances, particularly those listening on QMP ports. The use of firewall rules to block unnecessary QMP ports and implementing authentication mechanisms for QMP connections can significantly reduce the attack surface. Additionally, monitoring for unusual QMP command patterns and implementing intrusion detection systems can help identify potential exploitation attempts. This vulnerability aligns with ATT&CK technique T1059.001 Command and Scripting Interpreter: PowerShell and T1059.003 Command and Scripting Interpreter: Windows Command Shell, demonstrating how command injection flaws can be leveraged to achieve persistent access and system compromise in virtualized environments.