SMM stack disclosure via reused NVRAM length
Published Apr 5, 2024 · Updated Aug 2, 2024
Information disclosure in Lenovo Notebook BIOS firmware allows local users with elevated privileges to expose SMM stack memory through NVRAM. The 0xCA SMI handler lets SmmGetVariable enlarge DataSize and then reuses that length in SmmSetVariable, copying bytes beyond the initialized buffer into SaSetup. Kernel-level access is required; disclosed stack contents expose SMM addresses and support privilege escalation into System Management Mode.
Summary
What happened
Information disclosure in Lenovo Notebook BIOS firmware allows local users with elevated privileges to expose SMM stack memory through NVRAM. The 0xCA SMI handler lets SmmGetVariable enlarge DataSize and then reuses that length in SmmSetVariable, copying bytes beyond the initialized buffer into SaSetup. Kernel-level access is required; disclosed stack contents expose SMM addresses and support privilege escalation into System Management Mode.
The record
- CVE
- CVE-2023-5912
- Published
- Apr 5, 2024
- Updated
- Aug 2, 2024
- Vendor
- Lenovo
- Product
- Notebook BIOS
- Classifications
- CWE-787, T1542.001, T1068
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Apr 5, 2024CVE publishedPublication date reported by the CVE source.
- Aug 2, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=various
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
- Runtime SMM stack disclosure proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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