CVE-2023-31364 in EPYC 7001 Processors
Summary
by MITRE • 02/26/2026
Improper handling of direct memory writes in the input-output memory management unit could allow a malicious guest virtual machine (VM) to flood a host with writes, potentially causing a fatal machine check error resulting in denial of service.
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Analysis
by VulDB Data Team • 02/26/2026
The vulnerability identified as CVE-2023-31364 represents a critical flaw in virtualization environments where the input-output memory management unit (IOMMU) fails to properly handle direct memory writes from guest virtual machines. This issue manifests when malicious or compromised virtual machines attempt to exploit improper memory management controls, creating a scenario where excessive memory operations can overwhelm the host system's memory subsystem. The vulnerability specifically targets the IOMMU's ability to validate and control memory access patterns, allowing unauthorized direct memory writes that bypass normal protection mechanisms. Such flaws are particularly dangerous in virtualized environments where multiple tenants share the same physical hardware, as they can potentially be leveraged to disrupt service availability across the entire host system.
The technical implementation of this vulnerability stems from inadequate validation of memory access requests originating from guest VMs within the IOMMU framework. When a guest VM attempts to perform direct memory writes, the system should enforce strict boundaries and validation checks to prevent malicious or excessive memory operations. However, in the affected implementations, these controls are insufficient or improperly configured, enabling a single compromised VM to flood the host with memory write operations. The flaw operates at the hardware virtualization layer where memory management unit operations intersect with guest operating system memory access patterns, creating a pathway for memory exhaustion attacks. This improper handling can lead to system instability as the host's memory subsystem becomes overwhelmed by the volume of malicious write operations, ultimately triggering machine check errors that result in system crashes or complete service disruption.
The operational impact of CVE-2023-31364 extends beyond simple denial of service, as it can compromise the integrity of entire virtualized infrastructures. Attackers exploiting this vulnerability can potentially cause cascading failures across multiple VMs hosted on the same physical system, leading to widespread service outages. The vulnerability particularly affects cloud computing environments and data centers where virtualization is extensively utilized, as a single malicious tenant could potentially bring down the entire host server or cluster. From an attack perspective, this flaw aligns with techniques described in the attack tactic of privilege escalation and denial of service within the MITRE ATT&CK framework, specifically targeting virtualization environments and memory management components. The vulnerability also maps to CWE-129, which addresses improper validation of input, and CWE-775, which covers missing file descriptor closing, as the issue involves improper handling of memory access operations and resource management.
Mitigation strategies for CVE-2023-31364 require both immediate patching and architectural considerations to prevent exploitation. Organizations should prioritize applying vendor-specific patches that address the IOMMU memory handling implementation, as these updates typically include enhanced validation mechanisms and stricter access controls for direct memory operations. System administrators should implement monitoring solutions that can detect unusual memory access patterns from guest VMs, enabling early detection of potential exploitation attempts. Additionally, virtualization administrators should consider implementing resource quotas and memory limits for individual VMs to prevent any single tenant from overwhelming host resources. The solution approach aligns with defensive techniques outlined in the NIST Cybersecurity Framework, emphasizing the importance of protecting critical infrastructure components and implementing robust access controls. Organizations should also conduct regular vulnerability assessments focusing on virtualization environments and memory management components, ensuring that all systems maintain updated security configurations that prevent unauthorized memory access patterns and maintain system stability under potential attack conditions.