How severe is CVE-2021-33625?

CVE-2021-33625 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-33625 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33625?

CVE-2021-33625 primarily affects Insyde Insydeh2o. In total, 18 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-33625?

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-2021-33625 published?

CVE-2021-33625 was published on 2022-02-03 and last updated on 2026-08-11.

CVE-2021-33625

CVE-2021-33625 is a high-severity vulnerability in Insyde Insydeh2o with a CVSS 3.x base score of 7.5. 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-119.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 6.9
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Insyde Insydeh2o
Published: 2022-02-03
Last modified: 2026-08-11

Description

An issue was discovered in Kernel 5.x in Insyde InsydeH2O, affecting HddPassword. 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.

Frequently asked questions

What is CVE-2021-33625?: An issue was discovered in Kernel 5.x in Insyde InsydeH2O, affecting HddPassword. 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.
How severe is CVE-2021-33625?: CVE-2021-33625 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-33625 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33625?: CVE-2021-33625 primarily affects Insyde Insydeh2o. In total, 18 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-33625?: 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-2021-33625 published?: CVE-2021-33625 was published on 2022-02-03 and last updated on 2026-08-11.

References

Affected products (18)

cpe:2.3:a:insyde:insydeh2o:*:*:*:*:*:*:*:*
cpe:2.3:o:netapp:fas\/aff_bios:-:*:*:*:*:*:*:*
cpe:2.3:o:siemens:ruggedcom_ape1808_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_field_pg_m5_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc127e_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_itp1000_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc277g_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_ipc227g_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_ipc477e_pro_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_field_pg_m6_firmware:-:*:*:*:*:*:*:*

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