CVE-2021-41838: Insyde INSYDEH2O

High severity, CVSS 8.2. EPSS: 0.3% chance of exploitation in the next 30 days.

An issue was discovered in SdHostDriver in the kernel 5.0 through 5.5 in Insyde InsydeH2O. There is an SMM callout that allows an attacker to access the System Management Mode and execute arbitrary code. This occurs because of a Numeric Range Comparison Without a Minimum Check.

Affected products

• Insyde INSYDEH2O: from 5.1, before 5.16.42 (fixed in 5.16.42); from 5.2, before 5.26.42 (fixed in 5.26.42); from 5.3, before 5.35.42 (fixed in 5.35.42); from 5.4, before 5.43.42 (fixed in 5.43.42); from 5.5, before 5.51.42 (fixed in 5.51.42)
• Siemens SIMATIC Field Pg m5 Firmware: any version
• Siemens SIMATIC Field Pg m6 Firmware: any version
• Siemens SIMATIC IPC127E Firmware: any version
• Siemens SIMATIC IPC227G Firmware: any version
• Siemens SIMATIC IPC277G Firmware: any version
• Siemens SIMATIC IPC327G Firmware: any version
• Siemens SIMATIC IPC377G Firmware: any version
• Siemens SIMATIC IPC427E Firmware: any version
• Siemens SIMATIC IPC477E Firmware: any version
• Siemens SIMATIC IPC627E Firmware: any version
• Siemens SIMATIC IPC647E Firmware: any version
• Siemens SIMATIC IPC677E Firmware: any version
• Siemens SIMATIC IPC847E Firmware: any version
• Siemens SIMATIC ITP1000 Firmware: any version

Published 2022-02-03. Last modified 2026-08-11.