CVE-2025-0031 is a use-after-free vulnerability identified in the Secure Encrypted Virtualization (SEV) firmware of AMD EPYC™ 9004 Series processors. The flaw arises when a malicious hypervisor activates a migrated guest virtual machine (VM) configured with the SINGLE_SOCKET policy on a different physical CPU socket than the original migration agent. This mismatch can trigger a use-after-free condition in the SEV firmware, potentially leading to a loss of integrity within the guest VM environment. The vulnerability is rooted in improper handling of memory references during VM migration across sockets, which can be exploited by an attacker with high privileges on the hypervisor layer. The attack vector is local (AV:L), requiring the attacker to have elevated privileges (PR:H) on the hypervisor, but no user interaction (UI:N) or authentication (AT:N) is necessary. The vulnerability does not affect confidentiality, availability, or virtualization integrity beyond the scope of the single VM migration scenario (SI:L). Although no public exploits are known, the risk lies in the potential for a malicious hypervisor to compromise the integrity of guest VMs by manipulating migration policies and socket assignments. This vulnerability is significant in environments leveraging AMD EPYC 9004 processors with SEV technology, particularly in cloud and enterprise data centers where VM migration is routine. The CVSS 4.0 score of 4.6 reflects a medium severity due to the requirement for high privileges and the limited scope of impact. No patches or mitigation links are currently published, indicating the need for vigilance and proactive risk management by affected organizations.

For European organizations, the impact of CVE-2025-0031 centers on the integrity of virtualized workloads running on AMD EPYC 9004 Series processors with SEV enabled. Organizations relying on live VM migration across CPU sockets in multi-socket AMD EPYC environments could face risks of unauthorized modification or corruption of guest VM states if a malicious hypervisor is present. This could undermine trust in cloud service providers or internal private clouds using these processors. While confidentiality and availability are not directly impacted, integrity loss can lead to data corruption, application errors, or security policy violations, potentially affecting critical services and compliance with data protection regulations such as GDPR. The requirement for high privileges on the hypervisor limits the threat to insider attackers or compromised hypervisor components, but the complexity of modern cloud environments means this risk cannot be ignored. European data centers and cloud providers using AMD EPYC 9004 processors must consider this vulnerability in their threat models, especially those offering multi-tenant or sensitive workloads. The absence of known exploits reduces immediate risk but does not eliminate the need for mitigation and monitoring.

1. Restrict hypervisor administrative privileges strictly to trusted personnel and processes to reduce the risk of malicious hypervisor activity. 2. Enforce strict VM migration policies that prevent cross-socket migration of VMs configured with the SINGLE_SOCKET policy or disable such policies if not required. 3. Monitor VM migration logs and hypervisor events for unusual or unauthorized migration attempts, especially those involving socket changes. 4. Apply any forthcoming firmware or SEV firmware updates from AMD promptly once available to address this vulnerability. 5. Consider isolating critical workloads on dedicated sockets or physical hosts to minimize the attack surface related to socket migration. 6. Conduct regular security audits and penetration testing focused on hypervisor and VM migration security controls. 7. Collaborate with cloud service providers to ensure they have mitigations in place if using AMD EPYC 9004 processors. 8. Implement defense-in-depth strategies including hypervisor integrity monitoring and anomaly detection to identify potential exploitation attempts early.