HOMEVULNERABILITIESCVE-2021-33625
HIGH

CVE-2021-33625

CWE-119Published: February 3, 2022· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-33625 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.5.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

From a weakness classification perspective (CWE-119): Buffer overflow vulnerabilities can lead to arbitrary code execution or denial of service by corrupting adjacent memory.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityHigh
Privileges Req.High
User InteractionNone
ScopeChanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

Affected Vendors & Products

insyde1 product(s)
insydeh2o
netapp1 product(s)
fas\/aff bios
siemens32 product(s)
ruggedcom ape1808 firmwareruggedcom ape1808simatic field pg m5 firmwaresimatic field pg m5simatic ipc127e firmwaresimatic ipc127esimatic itp1000 firmwaresimatic itp1000simatic ipc277g firmwaresimatic ipc277gsimatic ipc227g firmwaresimatic ipc227g+20
Source: NVD CPE · 34 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

All References (9)

Quick Facts

CVE IDCVE-2021-33625
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-119
CISA KEVNo
Affected3 vendor(s)
PublishedFeb 3, 2022

Related CVEs (CWE-119)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2021-33625 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.