Advisory Published


First published: Thu Feb 03 2022(Updated: )

A vulnerability exists in System Management Interrupt (SWSMI) handler of InsydeH2O UEFI Firmware code located in SWSMI handler that dereferences gRT (EFI_RUNTIME_SERVICES) pointer to call a GetVariable service, which is located outside of SMRAM. This can result in code execution in SMM (escalating privilege from ring 0 to ring -2).

Credit: cve@mitre.org

Affected SoftwareAffected VersionHow to fix
Insyde InsydeH2O=
Insyde InsydeH2O=
Insyde InsydeH2O=
Insyde InsydeH2O=
Insyde InsydeH2O=
Insyde InsydeH2O=
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Frequently Asked Questions

  • What is the vulnerability ID for this vulnerability?

    The vulnerability ID for this vulnerability is CVE-2020-5953.

  • What software is affected by this vulnerability?

    The affected software includes InsydeH2O UEFI Firmware versions,,,,, and

  • What is the severity of CVE-2020-5953?

    The severity of CVE-2020-5953 is high, with a CVSS score of 7.5.

  • How does this vulnerability work?

    This vulnerability allows an attacker to execute arbitrary code in SMM (System Management Mode) by exploiting a vulnerability in the System Management Interrupt (SWSMI) handler of InsydeH2O UEFI Firmware.

  • Is there a fix available for this vulnerability?

    Yes, it is recommended to update to the latest version of InsydeH2O UEFI Firmware to mitigate this vulnerability.


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