In the AMD SEV/SEV-ES feature, memory can be rearranged in the guest address space that is not detected by the attestation mechanism which could be used by a malicious hypervisor to potentially lead to arbitrary code execution within the guest VM if a malicious administrator has access to compromise the server hypervisor.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-26311
• https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1004