Siemens InsydeH2O Inclusion of Functionality from Untrusted Control Sphere (CVE-2021-33626)

A vulnerability exists in SMM System Management Mode branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointerQWORD values for CommBuffer. This can be used by an attacker to corrupt data in SMRAM memory and even lead to arbitrary code executio...

CVE-2021-33626

CVE-2021-33626 affects InsydeH2O’s SMM code, specifically the SmmResourceCheckDxe driver, where a SWSMI handler registers without proper validation of the CommBuffer pointer, enabling data corruption in SMRAM and potential arbitrary code execution. Connected vendor disclosures confirm this vulner...