An attacker with access to a malicious hypervisor may be able to infer data values used in a SEV guest on AMD CPUs by monitoring ciphertext values over time.

hw: cpu: LFENCE/JMP Mitigation Update for CVE-2017-5715

LFENCE/JMP (mitigation V2-2) may not sufficiently mitigate CVE-2017-5715 on some AMD CPUs.

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.

hw: cpu: AMD CPUs may transiently execute beyond unconditional direct branch

Some AMD CPUs may transiently execute beyond unconditional direct branches, which may potentially result in data leakage.

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).

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.

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

Failure to flush the Translation Lookaside Buffer (TLB) of the I/O memory management unit (IOMMU) may lead an IO device to write to memory it should not be able to access, resulting in a potential loss of integrity.

AMD Secure Encrypted Virtualization

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.

A potential denial of service (DoS) vulnerability exists in the integrated chipset that may allow a malicious attacker to hang the system when it is rebooted.

AMD Secure Encrypted Virtualization

The lack of nested page table protection in the AMD SEV/SEV-ES feature could potentially lead to arbitrary code execution within the guest VM if a malicious administrator has access to compromise the server hypervisor.

AMD EPYC™ Processors contain an information disclosure vulnerability in the Secure Encrypted Virtualization with Encrypted State (SEV-ES) and Secure Encrypted Virtualization with Secure Nested Paging (SEV-SNP). A local authenticated attacker could potentially exploit this vulnerability leading to leaking guest data by the malicious hypervisor.

Insufficient validation of BIOS image length by ASP Firmware could lead to arbitrary code execution.

Secure Encrypted Virtualization (SEV) on Advanced Micro Devices (AMD) Platform Security Processor (PSP; aka AMD Secure Processor or AMD-SP) 0.17 build 11 and earlier has an insecure cryptographic implementation.