Describe CVE-2021-21556.
What is CVE-2021-21556?
Dell PowerEdge R640, R740, R740XD, R840, R940, R940xa, MX740c, MX840c, and T640 Server BIOS contain a stack-based buffer overflow vulnerability in systems with NVDIMM-N installed. A local malicious user with high privileges may potentially exploit this vulnerability, leading to a denial of Service, arbitrary code execution, or information disclosure in UEFI or BIOS Preboot Environment..