CVE-2021-33627 - CVE House
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Status published High CVE-2021-33627

An issue was discovered in Insyde InsydeH2O Kernel 5.0 before...

Vulnerability Description

An issue was discovered in Insyde InsydeH2O Kernel 5.0 before 05.09.11, 5.1 before 05.17.11, 5.2 before 05.27.11, 5.3 before 05.36.11, 5.4 before 05.44.11, and 5.5 before 05.52.11 affecting FwBlockServiceSmm. Software SMI services that use the Communicate() function of the EFI_SMM_COMMUNICATION_PROTOCOL do not check whether the address of the buffer is valid, which allows use of SMRAM, MMIO, or OS kernel addresses.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Affected Software

insydeh2o, simatic field pg m5 firmware, simatic field pg m6 firmware, simatic ipc127e firmware, simatic ipc227g firmware, simatic ipc277g firmware, simatic ipc327g firmware, simatic ipc377g firmware, simatic ipc427e firmware, simatic ipc477e firmware, simatic ipc627e firmware, simatic ipc647e firmware, simatic ipc677e firmware, simatic ipc847e firmware, simatic itp1000 firmware
Vulnerable Versions:
5.0, 5.1, 5.2, 5.3

Timeline

Official Publish: February 3rd, 2022
Last Modified: November 4th, 2025
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.