Advisory Published

CVE-2021-33627: Buffer Overflow

First published: Thu Feb 03 2022(Updated: )

An issue was discovered in Insyde InsydeH2O 5.x, 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

Credit: cve@mitre.org

Affected SoftwareAffected VersionHow to fix
Insyde InsydeH2O>=5.0<5.08.29
Insyde InsydeH2O>=5.1<5.16.29
Insyde InsydeH2O>=5.2<5.26.29
Insyde InsydeH2O>=5.3<5.35.29
Siemens Simatic Field Pg M5 Firmware
Siemens Simatic Field Pg M5
Siemens Simatic Field Pg M6 Firmware
Siemens Simatic Field Pg M6
Siemens Simatic Ipc127e Firmware
Siemens Simatic Ipc127e
Siemens Simatic Ipc227g Firmware
Siemens Simatic Ipc227g
Siemens Simatic Ipc277g Firmware
Siemens Simatic Ipc277g
Siemens Simatic Ipc327g Firmware
Siemens Simatic Ipc327g
Siemens Simatic Ipc377g Firmware
Siemens Simatic Ipc377g
Siemens Simatic Ipc427e Firmware
Siemens Simatic Ipc427e
Siemens Simatic Ipc477e Firmware
Siemens Simatic Ipc477e
Siemens Simatic Ipc627e Firmware
Siemens Simatic Ipc627e
Siemens Simatic Ipc647e Firmware
Siemens Simatic Ipc647e
Siemens Simatic Ipc677e Firmware
Siemens Simatic Ipc677e
Siemens Simatic Ipc847e Firmware
Siemens Simatic Ipc847e
Siemens Simatic Itp1000 Firmware
Siemens Simatic Itp1000

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Frequently Asked Questions

  • What is the vulnerability ID for this issue?

    The vulnerability ID for this issue is CVE-2021-33627.

  • What is the severity level of CVE-2021-33627?

    The severity level of CVE-2021-33627 is high with a CVSS score of 8.2.

  • What software is affected by CVE-2021-33627?

    Insyde InsydeH2O 5.x and Siemens Simatic Field Pg M5 Firmware are affected by CVE-2021-33627.

  • How does CVE-2021-33627 impact the affected software?

    CVE-2021-33627 allows an attacker to use SMRAM, MMIO, or OS kernel addresses through the Communicate() function of the EFI_SMM_COMMUNICATION_PROTOCOL.

  • Are there any available fixes for CVE-2021-33627?

    For available fixes, please refer to the vendor's security advisory and security pledge.


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