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.

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.

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.

Failure to assign a new report ID to an imported guest may potentially result in an SEV-SNP guest VM being tricked into trusting a dishonest Migration Agent (MA).

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.

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.

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.

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.

Improper validation of destination address in SVC_LOAD_FW_IMAGE_BY_INSTANCE and SVC_LOAD_BINARY_BY_ATTRIB in a malicious UApp or ABL may allow an attacker to overwrite arbitrary bootloader memory with SPI ROM contents resulting in a loss of integrity and availability.