Insydeh2o: Write-what-where Condition
CVE-2022-35408 is a high-severity write-what-where condition vulnerability in Insydeh2o from Insyde, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, without any action from a user. The record lists versions 5.17.38, 05.27.28, 05.36.28 as the first without the flaw, so updating Insydeh2o to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.37% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Insydeh2o to 5.17.38 or 05.27.28 or 05.36.28 or 05.44.28, whichever matches your release line, or a later version.
- Read the advisory on insyde.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Insyde | Insydeh2o | 5.1 up to, but not including, 5.17.38; 5.2 up to, but not including, 05.27.28; 5.3 up to, but not including, 05.36.28; 5.4 up to, but not including, 05.44.28; 5.5 up to, but not including, 05.52.28; 5.0 up to, but not including, 05.09.38 | 5.17.38, 05.27.28, 05.36.28, 05.44.28, 05.52.28, 05.09.38 |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.2 | High | NVD |
| CVSS 3.1 | 8.2 | High | CISA (ADP) |
Official 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.)
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Write-what-where Condition
Any condition where the attacker has the ability to write an arbitrary value to an arbitrary location, often as the result of a buffer overflow.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
- Use OS-level preventative functionality integrated after the fact. Not a complete solution.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- binarly.io/advisories/BRLY-2022-022/index.htmlExploit, Third Party Advisory
Other vulnerabilities in Insydeh2o
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.4 High severity
- 7.4 High severity
- 7.4 High severity
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