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.

Insufficient input validation in the ASP Bootloader may enable a privileged attacker with physical access to expose the contents of ASP memory potentially leading to a loss of confidentiality.

TOCTOU in the ASP Bootloader may allow an attacker with physical access to tamper with SPI ROM records after memory content verification, potentially leading to loss of confidentiality or a denial of service.

Insufficient DRAM address validation in System Management Unit (SMU) may allow an attacker to read/write from/to an invalid DRAM address, potentially resulting in denial-of-service.

AMD Processors could provide weaker than expected security, caused by improper or unexpected behavior of the INVD instruction. A remote authenticated attacker could exploit this vulnerability to affect cache line write-back behavior of the CPU leading to a potential loss of guest virtual machine (VM) memory integrity.

A division-by-zero error on some AMD processors can potentially return speculative data resulting in loss of confidentiality.

Insufficient validation of inputs in SVCMAPUSERSTACK in the ASP (AMD Secure Processor) bootloader may allow an attacker with a malicious Uapp or ABL to send malformed or invalid syscall to the bootloader resulting in a potential denial of service and loss of integrity.

Insufficient validation in parsing Owner's Certificate Authority (OCA) certificates in SEV (AMD Secure Encrypted Virtualization) and SEV-ES user application can lead to a host crash potentially resulting in denial of service.

A compromised or malicious ABL or UApp could send a SHA256 system call to the bootloader, which may result in exposure of ASP memory to userspace, potentially leading to information disclosure.

A TOCTOU in ASP bootloader may allow an attacker to tamper with the SPI ROM following data read to memory potentially resulting in S3 data corruption and information disclosure.

Improper access control settings in ASP Bootloader may allow an attacker to corrupt the return address causing a stack-based buffer overrun potentially leading to arbitrary code execution.

Improper syscall input validation in the ASP Bootloader may allow a privileged attacker to read memory out-of-bounds, potentially leading to a denial-of-service.

Insufficient checks in SEV may lead to a malicious hypervisor disclosing the launch secret potentially resulting in compromise of VM confidentiality.

Insufficient input validation in SYSKEYDERIVE system call in a compromised user application or ABL may allow an attacker to corrupt ASP (AMD Secure Processor) OS memory which may lead to potential arbitrary code execution.

IBPB may not prevent return branch predictions from being specified by pre-IBPB branch targets leading to a potential information disclosure.

Execution unit scheduler contention may lead to a side channel vulnerability found on AMD CPU microarchitectures codenamed “Zen 1”, “Zen 2” and “Zen 3” that use simultaneous multithreading (SMT). By measuring the contention level on scheduler queues an attacker may potentially leak sensitive information.

A flaw was found in hw. Mis-trained branch predictions for return instructions may allow arbitrary speculative code execution under certain microarchitecture-dependent conditions.

A flaw was found in hw. Aliases in the branch predictor may cause some AMD processors to predict the wrong branch type, potentially leading to information disclosure.

A potential vulnerability in some AMD processors using frequency scaling may allow an authenticated attacker to execute a timing attack to potentially enable information disclosure.

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.

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 flaw was found in hw. This issue can cause AMD CPUs to transiently execute beyond unconditional direct branches.

A flaw was found in hw. The speculative execution window of AMD LFENCE/JMP mitigation (MITIGATION V2-2) may be large enough to be exploited on AMD CPUs.

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.

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).

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

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 SENDSTART command in the SEV Firmware may allow a local authenticated attacker to perform a denial of service of the PSP

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