Security readout for executives and security teams
Plain-English summary
This is a high-impact firmware flaw in InsydeH2O. If an attacker already has high local privileges before the operating system context described by the advisory, they may execute code in System Management Mode, a deeply privileged firmware layer that can undermine device trust.
Executive priority
Prioritize identification and firmware remediation for affected devices. This is not an internet-facing emergency based on provided evidence, but SMM compromise can defeat normal operating system controls, so unmanaged affected firmware represents a meaningful platform integrity risk.
Technical view
CVE-2022-35408 is an SMM callout vulnerability in UsbLegacyControlSmm affecting InsydeH2O kernel 5.0 through 5.5. The issue involves attacker-controlled EFI_BOOT_SERVICES function pointers before the USB SMI handler triggers, enabling possible arbitrary SMM code execution and privilege escalation.
Likely exposure
Exposure is limited to systems whose firmware includes InsydeH2O kernel 5.0 through 5.5 with UsbLegacyControlSmm. The source bundle does not name specific OEM models or CPEs, so exposure must be determined from firmware inventory, vendor advisories, and OEM BIOS release notes.
Exploitation context
CISA KEV is false in the provided bundle, and no cited source states active exploitation. The CVE notes local attack vector, low complexity, high privileges required, and no user interaction. It also states this is not exploitable from code running in the operating system.
Researcher notes
The public bundle gives strong vulnerability mechanics but weak asset mapping: affected vendor/product/CPE entries are n/a. Researchers should avoid assuming model coverage beyond InsydeH2O kernel 5.0 through 5.5 and UsbLegacyControlSmm until corroborated by OEM firmware data.
Mitigation direction
- Check Insyde advisory SA-2022031 and relevant OEM firmware guidance.
- Inventory systems using InsydeH2O kernel 5.0 through 5.5.
- Apply vendor or OEM firmware updates when available.
- Prioritize assets where firmware trust is business-critical.
- Do not rely on OS patching alone for firmware exposure.
Validation and detection
- Confirm firmware vendor, InsydeH2O kernel version, and SMM driver presence.
- Map affected firmware to exact OEM models and BIOS releases.
- Verify installed firmware is not within the vulnerable range.
- Review vendor release notes for CVE-2022-35408 or SA-2022031 references.
- Document assets where affected status remains unknown.
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.
CWE-123: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2022-35408 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
- High
- CVSS
- 8.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H1.56Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.2HighVector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.insyde.com/security-pledgeCVE reference · x_refsource_MISC
- https://www.insyde.com/security-pledge/SA-2022031CVE reference · x_refsource_MISC
- https://binarly.io/advisories/BRLY-2022-022/index.htmlCVE reference · x_refsource_MISC
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.
Write-what-where Condition
Write-what-where Condition represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.