CVE-2019-6501 in QEMU
Summary
by MITRE
In QEMU 3.1, scsi_handle_inquiry_reply in hw/scsi/scsi-generic.c allows out-of-bounds write and read operations.
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Analysis
by VulDB Data Team • 10/26/2024
The vulnerability identified as CVE-2019-6501 affects QEMU version 3.1 and represents a critical security flaw in the SCSI generic device implementation. This issue manifests within the scsi_handle_inquiry_reply function located in the hw/scsi/scsi-generic.c source file, where improper bounds checking allows attackers to manipulate memory access patterns. The vulnerability stems from insufficient validation of input data during SCSI inquiry command processing, creating opportunities for both out-of-bounds write and read operations that can compromise system integrity.
The technical nature of this flaw places it squarely within CWE-121, which describes "Stack-based Buffer Overflow" conditions where data is written beyond the boundaries of allocated buffers. In the context of virtualization, this vulnerability enables malicious actors to exploit the SCSI subsystem by crafting specially crafted inquiry commands that trigger memory corruption. The out-of-bounds write operations can overwrite adjacent memory regions, potentially leading to arbitrary code execution or denial of service conditions. Meanwhile, out-of-bounds read operations may expose sensitive data from memory locations that should remain protected, creating information disclosure risks.
From an operational perspective, this vulnerability poses significant threats to virtualized environments where QEMU serves as the hypervisor platform. Attackers could leverage this flaw to escape virtual machine isolation boundaries, potentially compromising the host system or other guest virtual machines running on the same infrastructure. The impact extends beyond simple memory corruption as it represents a potential privilege escalation vector that could allow attackers to gain unauthorized access to system resources. The vulnerability affects any system utilizing QEMU 3.1 with SCSI devices, making it particularly dangerous in enterprise environments where virtualization is extensively deployed.
The ATT&CK framework categorizes this vulnerability under T1059.007 for "Command and Scripting Interpreter: Python" and T1068 for "Exploitation for Privilege Escalation" based on the potential for code execution and system compromise. Organizations should prioritize immediate mitigation through QEMU version updates to address the vulnerability, as the out-of-bounds write and read operations create multiple attack vectors for exploitation. Additionally, implementing network segmentation and access controls around virtualization infrastructure can help limit potential attack surfaces. The vulnerability highlights the critical importance of proper input validation in virtualization components and demonstrates how flaws in device emulation can lead to severe security implications across entire virtualized environments.