In SEV guest VMs, the CPU may fail to flush the Translation Lookaside Buffer (TLB) following a particular sequence of operations that includes creation of a new virtual machine control block (VMCB). The failure to flush the TLB may cause the microcode to use stale TLB translations which may allow for disclosure of SEV guest memory contents. Users of SEV-ES/SEV-SNP guest VMs are not impacted by this vulnerability.

A malicious hypervisor in conjunction with an unprivileged attacker process inside an SEV/SEV-ES guest VM may fail to flush the Translation Lookaside Buffer (TLB) resulting in unexpected behavior inside the virtual machine (VM).

A bug in AMD CPU’s core logic may allow for an attacker, using specific code from an unprivileged VM, to trigger a CPU core hang resulting in a potential denial of service. AMD believes the specific code includes a specific x86 instruction sequence that would not be generated by compilers.

Improper access controls in System Management Unit (SMU) may allow for an attacker to override performance control tables located in DRAM resulting in a potential lack of system resources.

Insufficient DRAM address validation in System Management Unit (SMU) may result in a DMA read from invalid DRAM address to SRAM resulting in SMU not servicing further requests.

Insufficient bounds checking in System Management Unit (SMU) may cause invalid memory accesses/updates that could result in SMU hang and subsequent failure to service any further requests from other components.

Improper input and range checking in the AMD Secure Processor (ASP) boot loader image header may allow an attacker to use attacker-controlled values prior to signature validation potentially resulting in arbitrary code execution.

Failure to verify SEV-ES TMR is not in MMIO space, SEV-ES FW could result in a potential loss of integrity or availability.

AMD System Management Unit (SMU) contains a potential issue where a malicious user may be able to manipulate mailbox entries leading to arbitrary code execution.

AMD System Management Unit (SMU) may experience a heap-based overflow which may result in a loss of resources.

AMD System Management Unit (SMU) may experience an integer overflow when an invalid length is provided which may result in a potential loss of resources.

Insufficient validation of guest context in the SNP Firmware could lead to a potential loss of guest confidentiality.

Failure to validate VM_HSAVE_PA during SNP_INIT may result in a loss of memory integrity.

Insufficient input validation in the SNP_GUEST_REQUEST command may lead to a potential data abort error and a denial of service.

A bug with the SEV-ES TMR may lead to a potential loss of memory integrity for SNP-active VMs.

Failure to validate SEV Commands while SNP is active may result in a potential impact to memory integrity.

Persistent platform private key may not be protected with a random IV leading to a potential “two time pad attack”.

Insufficient ID command validation in the SEV Firmware may allow a local authenticated attacker to perform a denial of service of the PSP.

Insufficient validation of the AMD SEV Signing Key (ASK) in the SEND_START command in the SEV Firmware may allow a local authenticated attacker to perform a denial of service of the PSP

When the AMD Platform Security Processor (PSP) boot rom loads, authenticates, and subsequently decrypts an encrypted FW, due to insufficient verification of the integrity of decrypted image, arbitrary code may be executed in the PSP when encrypted firmware images are used.