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. When SMT is enabled, certain AMD processors may speculatively execute instructions using a target from the sibling thread after an SMT mode switch potentially resulting in information disclosure.

References: https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1045 https://www.openwall.com/lists/oss-security/2023/02/14/4 https://xenbits.xen.org/xsa/advisory-426.html https://kernel.org/doc/html//next/admin-guide/hw-vuln/cross-thread-rsb.html

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.

Improper initialization of variables in the DXE driver may allow a privileged user to leak sensitive information via local access.

Improper initialization of variables in the DXE driver may allow a privileged user to leak sensitive information via local access.

Failure to validate the integer operand in ASP (AMD Secure Processor) bootloader may allow an attacker to introduce an integer overflow in the L2 directory table in SPI flash resulting in a potential denial of service.

Improper bounds checking in APCB firmware may allow an attacker to perform an out of bounds write, corrupting the APCB entry, potentially leading to arbitrary code execution.

Improper Access Control in the AMD SPI protection feature may allow a user with Ring0 (kernel mode) privileged access to bypass protections potentially resulting in loss of integrity and availability.

Insufficient control flow management in AmdCpmGpioInitSmm may allow a privileged attacker to tamper with the SMM handler potentially leading to escalation of privileges.

Insufficient control flow management in AmdCpmOemSmm may allow a privileged attacker to tamper with the SMM handler potentially leading to an escalation of privileges.

Certain size values in firmware binary headers could trigger out of bounds reads during signature validation, leading to denial of service or potentially limited leakage of information about out-of-bounds memory contents.

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.

Insufficient bounds checking in ASP may allow an attacker to issue a system call from a compromised ABL which may cause arbitrary memory values to be initialized to zero, potentially leading to a loss of integrity.

Improper access control in System Management Mode (SMM) may allow an attacker to write to SPI ROM potentially leading to arbitrary code execution.

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.

Insufficient General Purpose IO (GPIO) bounds check in System Management Unit (SMU) may result in access/updates from/to invalid address space that could result in denial of service.

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 malformed SMI (System Management Interface) command may allow an attacker to establish a corrupted SMI Trigger Info data structure, potentially leading to out-of-bounds memory reads and writes when triggering an SMI resulting in a potential loss of resources.

A malicious or compromised UApp or ABL may coerce the bootloader into corrupting arbitrary memory potentially leading to loss of integrity of data.

Improper validation of the BIOS directory may allow for searches to read beyond the directory table copy in RAM, exposing out of bounds memory contents, resulting in a potential denial of service.

An attacker with root account privileges can load any legitimately signed firmware image into the Audio Co-Processor (ACP,) irrespective of the respective signing key being declared as usable for authenticating an ACP firmware image, potentially resulting in a denial of service.

Insufficient bound checks in the System Management Unit (SMU) may result in access to an invalid address space that could result in denial of service.

Insufficient checks in System Management Unit (SMU) FeatureConfig may result in reenabling features potentially resulting in denial of resources and/or denial of service.

Insufficient bound checks in the System Management Unit (SMU) may result in a system voltage malfunction that could result in denial of resources and/or possibly denial of service.

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.