8.2

CVE-2021-33627: insyde insydeh2o

CVSS: 8.2v3.1HighModified
Published 03-02-2022Last modified 11-08-2026
Open JSON

Vulnerability summary

CVE-2021-33627 is a high (CVSS 8.2) vulnerability in insyde insydeh2o. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 24.4% of scored vulnerabilities.

Overall risk
33/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.2/10
010
High · v3.1 (NVD)
EPSS score
0.33%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 03-02-2022
    PublishedVulnerability first disclosed.
  2. 11-08-2026
    Last modifiedVulnerability information updated.

Description

An issue was discovered in Insyde InsydeH2O Kernel 5.0 before 05.09.11, 5.1 before 05.17.11, 5.2 before 05.27.11, 5.3 before 05.36.11, 5.4 before 05.44.11, and 5.5 before 05.52.11 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.

CVSS metrics

2 scores · 1 source · 2 versions

EPSS trend

Probability

0.33%

Chance of exploitation in the next 30 days

Percentile

24%

Versus all other CVEs

30-day change

0.00 pp

From 0.33% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.33%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Insyde1 product
  • insydeh2o≥ 5.0, < 5.08.29 | ≥ 5.1, < 5.16.29 | ≥ 5.2, < 5.26.29 | ≥ 5.3, < 5.35.29

1 vendor · 1 product

References

6 links