SMRAM disclosure via unchecked SMI source pointer
Published Sep 22, 2022 · Updated May 5, 2025
Information disclosure in InsydeH2O kernel 5.0 through 5.5 allows local users with DXE code execution to read SMRAM contents. The FwBlockServiceSmm SMI handler passes an unchecked communication-buffer address to memcpy or sub_800031CC, copying SMRAM bytes into the caller's destination. Exploitation requires attacker-controlled code during the DXE boot phase; the primitive discloses SMRAM addresses but does not itself write firmware or execute SMM code.
Summary
What happened
Information disclosure in InsydeH2O kernel 5.0 through 5.5 allows local users with DXE code execution to read SMRAM contents. The FwBlockServiceSmm SMI handler passes an unchecked communication-buffer address to memcpy or sub_800031CC, copying SMRAM bytes into the caller's destination. Exploitation requires attacker-controlled code during the DXE boot phase; the primitive discloses SMRAM addresses but does not itself write firmware or execute SMM code.
The record
- CVE
- CVE-2022-35894
- Published
- Sep 22, 2022
- Updated
- May 5, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-401
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Sep 22, 2022CVE publishedPublication date reported by the CVE source.
- May 5, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Binarly BRLY-2022-018 technical proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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