CVE-2020-5953

A vulnerability exists in System Management Interrupt (SWSMI) handler of InsydeH2O UEFI Firmware...

7.5 High

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).

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: High
Privileges needed: High
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.28%Down 0.8 points since Feb 3, 2022

What each source reports

NVD Score used 7.5

Record: CVE-2020-5953
CVSS 3.1: 7.5 HighCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
CVSS 2.0: 6.9 MediumAV:L/AC:M/Au:N/C:C/I:C/A:C
Updated: 2026-11-02

CVE List No score

Record: CVE-2020-5953
Updated: 2026-11-02

EUVDEUVD-2020-27107 No score

Record: EUVD-2020-27107
Updated: 2026-11-02

GitHub AdvisoriesGHSA-f8pw-77pg-8gv6 7.5

A vulnerability exists in System Management Interrupt (SWSMI) handler of InsydeH2O UEFI Firmware...

Record: GHSA-f8pw-77pg-8gv6
CVSS 3.1: 7.5 HighCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
Updated: 2026-11-02

Affected products

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History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2020-5953 is a high vulnerability (CVSS 7.5) in Insyde Insydeh2o, published February 3, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.28%, the 21st percentile. No source names a fixed version.