Improper re-initialization of IOMMU during the DRTM event may permit an untrusted platform configuration to persist, allowing an attacker to read or modify hypervisor memory, potentially resulting in loss of confidentiality, integrity, and availability.

IOMMU improperly handles certain special address ranges with invalid device table entries (DTEs), which may allow an attacker with privileges and a compromised Hypervisor to induce DTE faults to bypass RMP checks in SEV-SNP, potentially leading to a loss of guest integrity.

A TOCTOU (Time-Of-Check-Time-Of-Use) in SMM may allow an attacker with ring0 privileges and access to the BIOS menu or UEFI shell to modify the communications buffer potentially resulting in arbitrary code execution.

An out of bounds memory write when processing the AMD PSP1 Configuration Block (APCB) could allow an attacker with access the ability to modify the BIOS image, and the ability to sign the resulting image, to potentially modify the APCB block resulting in arbitrary code execution.

Improper restriction of write operations in SNP firmware could allow a malicious hypervisor to potentially overwrite a guest's memory or UMC seed resulting in loss of confidentiality and integrity.

Improper input validation in SEV-SNP could allow a malicious hypervisor to read or overwrite guest memory potentially leading to data leakage or data corruption.

Improper restriction of write operations in SNP firmware could allow a malicious hypervisor to overwrite a guest's UMC seed potentially allowing reading of memory from a decommissioned guest.

Due to a code bug in Secure_TSC, SEV firmware may allow an attacker with high privileges to cause a guest to observe an incorrect TSC when Secure TSC is enabled potentially resulting in a loss of guest integrity.  

Failure to initialize memory in SEV Firmware may allow a privileged attacker to access stale data from other guests.

A privileged attacker can prevent delivery of debug exceptions to SEV-SNP guests potentially resulting in guests not receiving expected debug information.