Security readout for executives and security teams
Plain-English summary
This is a firmware-level memory corruption issue in InsydeH2O 5.x. Certain SMM drivers failed to validate communication buffer inputs, which could let a caller corrupt firmware or operating-system memory. Firmware issues can carry high operational impact because remediation often depends on OEM firmware updates, not normal application patching.
Executive priority
Prioritize this for firmware governance and vendor follow-up, especially on appliances and critical infrastructure products. The urgency is driven by potential firmware or OS memory corruption and remediation dependency on vendor firmware updates. There is no provided evidence of active exploitation.
Technical view
CVE-2020-27339 affects certain InsydeH2O 5.x kernel SMM drivers that mishandled CommBuffer and CommBufferSize validation. The CVE names AhciBusDxe, IdeBusDxe, NvmExpressDxe, SdHostDriverDxe, and SdMmcDeviceDxe fixed driver versions for Kernel 5.1 through 5.5. The source bundle does not provide CVSS, CWE, privilege requirements, or exploit details.
Likely exposure
Exposure is most likely on systems or products shipping affected InsydeH2O 5.x firmware. The public references include Insyde, CERT/CC, NetApp, and Siemens advisories, so asset owners should verify applicability through their OEM or product vendor rather than assuming all Insyde-based devices are affected.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. They also do not provide a public exploit path, required privileges, or attack vector. Treat this as a serious firmware integrity issue, but do not claim exploitation without additional vendor or threat-intelligence evidence.
Researcher notes
The source bundle lacks CVSS, CWE, attack vector, exploitability, and product-specific affected-version details. Analysis should stay tied to the named InsydeH2O 5.x SMM drivers and downstream vendor advisories. Avoid broad claims about all devices using Insyde firmware.
Mitigation direction
- Check OEM and product-vendor advisories for CVE-2020-27339 applicability.
- Update firmware to versions containing the fixed InsydeH2O driver builds.
- Prioritize exposed, high-value, appliance, and operational technology assets for vendor verification.
- Track NetApp and Siemens guidance where those product families are present.
- If no update is available, request vendor remediation guidance and document risk acceptance.
Validation and detection
- Inventory assets using InsydeH2O 5.x firmware or affected downstream products.
- Confirm whether the named SMM drivers are present in the firmware image.
- Compare driver versions against the fixed versions listed in the CVE description.
- Verify installed firmware against OEM, Insyde, NetApp, or Siemens advisory status.
- Record unaffected determinations with source advisory evidence.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-2020-27339 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.insyde.com/security-pledge/SA-2021001CVE reference · x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20220216-0005/CVE reference · x_refsource_CONFIRM
- https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdfCVE reference · x_refsource_CONFIRM
- https://www.kb.cert.org/vuls/id/796611CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.