How severe is CVE-2021-42554?

CVE-2021-42554 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-42554 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42554?

CVE-2021-42554 primarily affects Insyde Insydeh2o. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-42554?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-42554 published?

CVE-2021-42554 was published on 2022-02-03 and last updated on 2026-06-17.

CVE-2021-42554

CVE-2021-42554 is a high-severity vulnerability in Insyde Insydeh2o with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 8.2)
CVSS v2: 7.2
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Insyde Insydeh2o
Published: 2022-02-03
Last modified: 2026-06-17

Description

An issue was discovered in Insyde InsydeH2O with Kernel 5.0 before 05.08.42, Kernel 5.1 before 05.16.42, Kernel 5.2 before 05.26.42, Kernel 5.3 before 05.35.42, Kernel 5.4 before 05.42.51, and Kernel 5.5 before 05.50.51. An SMM memory corruption vulnerability in FvbServicesRuntimeDxe allows a possible attacker to write fixed or predictable data to SMRAM. Exploiting this issue could lead to escalating privileges to SMM.

Frequently asked questions

What is CVE-2021-42554?: An issue was discovered in Insyde InsydeH2O with Kernel 5.0 before 05.08.42, Kernel 5.1 before 05.16.42, Kernel 5.2 before 05.26.42, Kernel 5.3 before 05.35.42, Kernel 5.4 before 05.42.51, and Kernel 5.5 before 05.50.51. An SMM memory corruption vulnerability in FvbServicesRuntimeDxe allows a possible attacker to write fixed or predictable data to SMRAM. Exploiting this issue could lead to escalating privileges to SMM.
How severe is CVE-2021-42554?: CVE-2021-42554 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-42554 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42554?: CVE-2021-42554 primarily affects Insyde Insydeh2o. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-42554?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-42554 published?: CVE-2021-42554 was published on 2022-02-03 and last updated on 2026-06-17.

References

Affected products (16)

cpe:2.3:a:insyde:insydeh2o:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_field_pg_m5_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_field_pg_m6_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc127e_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc227g_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc277g_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc327g_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc377g_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc427e_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc477e_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc627e_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc647e_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc677e_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc847e_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_itp1000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:ruggedcom_ape1808_firmware:*:*:*:*:*:*:*:*

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