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.

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.

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.

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

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

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

Failure to validate the communication buffer and communication service in the BIOS may allow an attacker to tamper with the buffer resulting in potential SMM (System Management Mode) arbitrary code execution.

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

Insufficient verification of missing size check in 'LoadModule' may lead to an out-of-bounds write potentially allowing an attacker with privileges to gain code execution of the OS/kernel by loading a malicious TA.

Insufficient memory cleanup in the AMD Secure Processor (ASP) Trusted Execution Environment (TEE) may allow an authenticated attacker with privileges to generate a valid signed TA and potentially poison the contents of the process memory with attacker controlled data resulting in a loss of confidentiality.

Improper parameters handling in AMD Secure Processor (ASP) drivers may allow a privileged attacker to elevate their privileges potentially leading to loss of integrity.

Improper parameters handling in the AMD Secure Processor (ASP) kernel may allow a privileged attacker to elevate their privileges potentially leading to loss of integrity.

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 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.

A malicious or compromised UApp or ABL may be used by an attacker to issue a malformed system call to the Stage 2 Bootloader potentially leading to corrupt memory and code execution.

Failure to verify the protocol in SMM may allow an attacker to control the protocol and modify SPI flash resulting in a potential arbitrary code execution.

Insufficient check of the process type in Trusted OS (TOS) may allow an attacker with privileges to enable a lesser privileged process to unmap memory owned by a higher privileged process resulting in a denial of service.

A malicious or compromised User Application (UApp) or AGESA Boot Loader (ABL) could be used by an attacker to exfiltrate arbitrary memory from the ASP stage 2 bootloader potentially leading to information disclosure.

A malicious or compromised UApp or ABL may be used by an attacker to issue a malformed system call which results in mapping sensitive System Management Network (SMN) registers leading to a loss of integrity and availability.

An attacker, who gained elevated privileges via some other vulnerability, may be able to read data from Boot ROM resulting in a loss of system integrity.

A malicious or compromised UApp or ABL may be used by an attacker to send a malformed system call to the bootloader, resulting in out-of-bounds memory accesses.

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.

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.

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 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.

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.