CVE-2020-27339: Insyde INSYDEH2O

Medium severity, CVSS 6.7. EPSS: 0.3% chance of exploitation in the next 30 days.

In the kernel in Insyde InsydeH2O 5.x, certain SMM drivers did not correctly validate the CommBuffer and CommBufferSize parameters, allowing callers to corrupt either the firmware or the OS memory. The fixed versions for this issue in the AhciBusDxe, IdeBusDxe, NvmExpressDxe, SdHostDriverDxe, and SdMmcDeviceDxe drivers are 05.16.25, 05.26.25, 05.35.25, 05.43.25, and 05.51.25 (for Kernel 5.1 through 5.5).

Affected products

• Insyde INSYDEH2O: from 5.3, before 5.34.44 (fixed in 5.34.44); from 5.2, before 5.25.44 (fixed in 5.25.44); from 5.1, before 5.16.25 (fixed in 5.16.25); from 5.4, before 5.42.44 (fixed in 5.42.44); from 5.3, before 5.35.25 (fixed in 5.35.25); from 5.2, before 5.26.25 (fixed in 5.26.25); …
• Siemens Ruggedcom APR1808 Firmware: affected versions not specified
• Siemens SIMATIC Field Pg m5 Firmware: affected versions not specified
• Siemens SIMATIC Field Pg m6 Firmware: affected versions not specified
• Siemens SIMATIC IPC127E Firmware: affected versions not specified
• Siemens SIMATIC IPC227G Firmware: affected versions not specified
• Siemens SIMATIC IPC277G Firmware: affected versions not specified
• Siemens SIMATIC IPC327G Firmware: affected versions not specified
• Siemens SIMATIC IPC377G Firmware: affected versions not specified
• Siemens SIMATIC IPC427E Firmware: affected versions not specified
• Siemens SIMATIC IPC477E Firmware: affected versions not specified
• Siemens SIMATIC IPC477E Pro Firmware: affected versions not specified
• Siemens SIMATIC IPC627E Firmware: affected versions not specified
• Siemens SIMATIC IPC647E Firmware: affected versions not specified
• Siemens SIMATIC IPC677E Firmware: affected versions not specified
• Siemens SIMATIC IPC847E Firmware: affected versions not specified
• Siemens SIMATIC ITP1000 Firmware: affected versions not specified

Published 2021-06-16. Last modified 2026-08-11.