CVE-2024-8354 is a vulnerability identified in the QEMU virtualization platform, specifically within the usb_ep_get() function located in hw/net/core.c. The flaw manifests as an assertion failure when the function attempts to retrieve a USB endpoint from a USB device. This assertion failure can be triggered by a malicious, unprivileged user operating within a guest virtual machine. By exploiting this flaw, the attacker can cause the QEMU process running on the host system to crash, leading to a denial of service (DoS) condition. The vulnerability does not allow for privilege escalation, data leakage, or integrity compromise; its impact is limited to availability by terminating the host's QEMU process. The CVSS v3.1 base score is 5.5, with vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, indicating that exploitation requires local access with low privileges, no user interaction, and affects availability only. There are no known exploits in the wild at the time of publication. The vulnerability affects QEMU versions prior to the patch release, though specific affected versions were not detailed. The root cause is an unchecked assertion in the USB device emulation code, which can be triggered by malformed or unexpected USB endpoint requests from the guest. This vulnerability is particularly relevant for environments that allow USB device passthrough or emulate USB devices in guest VMs. Attackers with access to the guest can leverage this to disrupt host operations, potentially impacting service availability in virtualized environments.

For European organizations, the primary impact of CVE-2024-8354 is the potential for denial of service on hosts running QEMU-based virtualization. This can disrupt critical services hosted on virtual machines, including cloud infrastructure, enterprise applications, and development environments. Organizations relying on USB device passthrough or emulation in their virtualized environments are at higher risk. The disruption caused by a QEMU process crash could lead to downtime, loss of productivity, and potential cascading effects if multiple VMs or services depend on the affected host. While the vulnerability does not compromise data confidentiality or integrity, availability impacts can be significant, especially in sectors such as finance, healthcare, and critical infrastructure where uptime is crucial. Additionally, the requirement for local guest access means that insider threats or compromised guest VMs could exploit this vulnerability to disrupt host operations. European cloud service providers and data centers using QEMU extensively may face operational risks if this vulnerability is not addressed promptly.

1. Apply official patches from QEMU or your virtualization vendor as soon as they become available to address the assertion failure in usb_ep_get(). 2. Temporarily disable or restrict USB device passthrough and emulation in guest VMs, especially if not required, to reduce the attack surface. 3. Implement strict access controls and monitoring for guest VM users to prevent unauthorized or malicious activity within guests. 4. Monitor QEMU host processes for unexpected crashes or restarts that could indicate exploitation attempts. 5. Use virtualization management tools to isolate critical workloads and limit the impact of a single VM compromise. 6. Conduct regular security audits of virtualization environments focusing on USB device configurations and guest access policies. 7. Educate administrators and users about the risks of local guest exploitation and enforce least privilege principles within guest VMs. 8. Consider deploying intrusion detection or anomaly detection systems that can identify unusual USB device requests or QEMU process behavior.