CVE-2014-5388 in QEMU
Summary
by MITRE
Off-by-one error in the pci_read function in the ACPI PCI hotplug interface (hw/acpi/pcihp.c) in QEMU allows local guest users to obtain sensitive information and have other unspecified impact related to a crafted PCI device that triggers memory corruption.
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Analysis
by VulDB Data Team • 02/11/2022
The vulnerability identified as CVE-2014-5388 represents a critical off-by-one error within the ACPI PCI hotplug interface implementation of QEMU virtualization software. This flaw exists in the pci_read function located in the hw/acpi/pcihp.c source file, where improper boundary checking allows unauthorized access to memory regions that should remain protected. The vulnerability specifically affects the virtualized PCI device handling mechanisms that enable dynamic insertion and removal of PCI devices within virtual machine environments, creating a pathway for privilege escalation and information disclosure attacks.
The technical nature of this vulnerability stems from an insufficient bounds check during PCI configuration space reads, where the function fails to properly validate the requested memory access boundaries. When a malicious guest user crafts a specially designed PCI device configuration that triggers this code path, the off-by-one error causes the system to read one byte beyond the intended memory buffer, potentially exposing kernel memory contents to the guest operating system. This memory corruption vulnerability can lead to sensitive information disclosure including kernel stack contents, memory addresses, and potentially credentials or cryptographic keys stored in adjacent memory regions. The flaw operates at the hypervisor level, making it particularly dangerous as it can be exploited by unprivileged users within the guest operating system to gain unauthorized access to the underlying host system's memory space.
From an operational impact perspective, this vulnerability creates significant security risks for virtualized environments where multiple tenants share the same physical hardware. The attack vector allows local guest users to potentially extract sensitive data from the host kernel memory, which could include cryptographic keys, passwords, or other confidential information. The unspecified nature of the additional impacts suggests that this memory corruption could potentially lead to more severe consequences including denial of service conditions or privilege escalation to root-level access within the virtualized environment. This vulnerability directly impacts the security isolation guarantees that virtualization platforms are designed to provide, undermining the fundamental security model of containerized and virtualized computing environments.
The vulnerability aligns with CWE-129, which describes improper validation of array indices, and represents a classic example of memory safety issues in hypervisor implementations. From an attack framework perspective, this flaw maps to several ATT&CK techniques including privilege escalation through kernel exploitation and credential access via information disclosure. The attack requires minimal privileges within the guest environment, making it particularly dangerous as it can be exploited by any user with access to the virtual machine. Organizations using QEMU-based virtualization solutions should prioritize immediate patching, as the vulnerability can be exploited without requiring network access or special privileges beyond standard guest user access. Mitigation strategies include applying the relevant QEMU security patches, implementing strict guest user access controls, and monitoring for unusual memory access patterns in virtualized environments. The vulnerability also highlights the importance of rigorous code review processes for hypervisor components and the need for comprehensive testing of device emulation code to prevent similar memory safety issues in virtualization platforms.