CVE-2025-29943 is a write-what-where vulnerability classified under CWE-123 that affects AMD EPYC™ 9004 Series processors. This flaw allows an attacker with administrative privileges on the host system to manipulate the CPU pipeline configuration. Specifically, the vulnerability can lead to corruption of the stack pointer within an SEV-SNP (Secure Encrypted Virtualization - Secure Nested Paging) guest environment. SEV-SNP is a security feature designed to protect virtual machines by encrypting their memory and ensuring integrity. By exploiting this vulnerability, an attacker could potentially undermine the isolation guarantees provided by SEV-SNP, leading to possible compromise of guest virtual machines. The attack requires local privileged access (administrator level) and does not require user interaction, limiting the attack surface to insiders or compromised administrators. The CVSS v4.0 base score of 4.6 reflects the limited attack vector (local), low complexity, and the requirement for high privileges but no user interaction or network access. No patches or mitigations have been published by AMD at the time of disclosure, and no known exploits are reported in the wild. This vulnerability highlights risks in hardware-level security features and the importance of securing administrative access in virtualized environments.

For European organizations, especially those operating cloud infrastructure, data centers, or virtualized environments using AMD EPYC 9004 Series processors, this vulnerability poses a risk to the confidentiality and integrity of virtual machines protected by SEV-SNP. Successful exploitation could allow an attacker with administrative privileges to corrupt critical CPU state, potentially leading to guest VM compromise or data leakage. This undermines trust in hardware-based security features and could impact sectors relying on secure virtualization, such as finance, healthcare, and government. Although the vulnerability requires high privileges and local access, insider threats or compromised administrators could exploit it. The lack of patches increases exposure time, and organizations may face compliance and reputational risks if sensitive data is compromised. The vulnerability does not directly affect availability but could lead to system instability or crashes if exploited.

1. Enforce strict administrative access controls and limit the number of users with high privileges on hosts running AMD EPYC 9004 processors. 2. Implement robust monitoring and auditing of administrative actions to detect suspicious behavior indicative of exploitation attempts. 3. Use hardware and software-based security solutions to detect anomalies in CPU pipeline behavior or virtualization integrity. 4. Isolate critical workloads and sensitive SEV-SNP guests on separate hosts with minimal administrative exposure. 5. Prepare for timely deployment of AMD patches or microcode updates once released, including testing in controlled environments. 6. Employ multi-factor authentication and privileged access management to reduce risk of credential compromise. 7. Regularly review and update virtualization and host security configurations to minimize attack surface. 8. Engage with AMD and security communities to stay informed on developments and recommended mitigations.