LiveActive security incident?Get immediate response
CVE Record

CVE-2021-45971: An issue was discovered in SdHostDriver in Insyde InsydeH2O with kernel 5.1 before 05.16.25, 5.2 before 05....

An issue was discovered in SdHostDriver in Insyde InsydeH2O with kernel 5.1 before 05.16.25, 5.2 before 05.26.25, 5.3 before 05.35.25, 5.4 before 05.43.25, and 5.5 before 05.51.25. A vulnerability exists in the SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointer (CommBufferData).

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a firmware-level issue in InsydeH2O SdHostDriver. Some firmware kernels before listed maintenance versions register an SMM software interrupt handler without enough validation of a communication buffer pointer. Exposure matters for devices using affected firmware, but the bundle provides no CVSS score, severity, or confirmed exploitation.

Executive priority

Prioritize discovery and vendor-confirmed firmware updates, especially for critical infrastructure and appliances. Business urgency is difficult to quantify because severity and affected products are incomplete, but firmware issues can be costly to remediate late.

Technical view

The vulnerable SMM branch registers a SWSMI handler that insufficiently checks or validates CommBufferData. The description names InsydeH2O kernel 5.1 before 05.16.25, 5.2 before 05.26.25, 5.3 before 05.35.25, 5.4 before 05.43.25, and 5.5 before 05.51.25.

Likely exposure

Organizations may be exposed through servers, appliances, embedded systems, or endpoints whose OEM firmware includes affected InsydeH2O SdHostDriver versions. The provided affected-product list is incomplete, so asset-level confirmation requires vendor or OEM firmware inventory.

Exploitation context

The source bundle does not cite active exploitation, public exploit availability, or CISA KEV listing. Treat exploitation status as unconfirmed. The issue is relevant because SMM vulnerabilities can affect firmware trust boundaries, but impact details are not fully specified here.

Researcher notes

Evidence is limited to a pointer-validation flaw in an SMM SWSMI handler for SdHostDriver. The bundle lacks CVSS, CWE, exploit notes, and complete product mapping. Avoid assuming exploitability beyond the stated validation weakness.

Mitigation direction

  • Check OEM or device-vendor advisories for firmware containing the corrected InsydeH2O kernel versions.
  • Prioritize firmware updates for exposed infrastructure, appliances, and managed endpoint fleets using affected firmware.
  • Use vendor-supported firmware packages; do not apply firmware from unrelated device models.
  • Track Siemens, NetApp, Insyde, and CERT guidance for product-specific remediation details.

Validation and detection

  • Inventory devices and firmware versions that use InsydeH2O or vendor firmware derived from it.
  • Map firmware kernel versions against the affected version ranges in the CVE description.
  • Review OEM advisories to confirm whether each device model is affected or already remediated.
  • Verify updated firmware reports a corrected version through vendor management tooling.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2021-45971 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
5Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.