The stack buffer overflow vulnerability in PlatformInitAdvancedPreMem leads to arbitrary code execution during PEI phase.

A potential attacker can execute an arbitrary code at the time of the PEI phase and influence the subsequent boot stages. This can lead to the mitigations bypassing, physical memory contents disclosure, discovery of any secrets from any Virtual Machines (VMs) and bypassing memory isolation and confidential computing boundaries. Additionally, an attacker can build a payload which can be injected into the SMRAM memory. This issue affects: Module name: PlatformInitAdvancedPreMem SHA256: 644044fdb8daea30a7820e0f5f88dbf5cd460af72fbf70418e9d2e47efed8d9b Module GUID: EEEE611D-F78F-4FB9-B868-55907F169280 This issue affects: AMI Aptio 5.x.