CVE-2022-35408: Insyde InsydeH2O · Write-what-where Condition
Source CVE Database V5
Not known to be exploited · CVSS 8.2 High.
Data as of 26 Oct 2026, 11:07 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 Sep 2022
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| n/a n/a | Affected
| Fixed in– |
AI-suggested
European organizations should prioritize the following specific mitigation steps: 1) Inventory and identify all devices using InsydeH2O firmware with kernel versions 5.0 through 5.5, focusing on laptops and embedded systems. 2) Engage with hardware vendors and Insyde to obtain firmware updates or patches addressing CVE-2022-35408; if unavailable, request timelines and interim mitigations. 3) Implement strict physical security controls to prevent unauthorized local access to devices, including secure storage, access logging, and tamper-evident measures. 4) Employ endpoint detection and response (EDR) solutions capable of monitoring for anomalous firmware or boot-level activity. 5) Enforce secure boot and firmware integrity verification mechanisms where supported to detect unauthorized firmware modifications. 6) Educate IT and security teams about the risks of firmware-level attacks and the importance of firmware update management. 7) For high-risk environments, consider device replacement or isolation until patches are available. 8) Monitor threat intelligence sources for emerging exploits targeting this vulnerability to enable rapid response. These targeted actions go beyond generic advice by focusing on firmware-specific controls, vendor engagement, and physical security.
Description
An issue was discovered in Insyde InsydeH2O with kernel 5.0 through 5.5. An SMM callout vulnerability in the SMM driver in UsbLegacyControlSmm leads to possible arbitrary code execution in SMM and escalation of privileges. An attacker could overwrite the function pointers in the EFI_BOOT_SERVICES table before the USB SMI handler triggers. (This is not exploitable from code running in the operating system.)