Memory disclosure via stale NVRAM variable size
Published Sep 12, 2023 · Updated Sep 26, 2024
Information disclosure in AMI Aptio V firmware allows local users to read stack or global memory through a crafted NVRAM variable. The affected DXE driver passes a DataSize value modified by GetVariable directly to SetVariable, writing memory beyond the intended four-byte value into AmiHardwareSignatureSetupUpdateCountVar. Reaching this path requires local access and user interaction; the disclosed memory supports a later DXE privilege-escalation chain.
Summary
What happened
Information disclosure in AMI Aptio V firmware allows local users to read stack or global memory through a crafted NVRAM variable. The affected DXE driver passes a DataSize value modified by GetVariable directly to SetVariable, writing memory beyond the intended four-byte value into AmiHardwareSignatureSetupUpdateCountVar. Reaching this path requires local access and user interaction; the disclosed memory supports a later DXE privilege-escalation chain.
The record
- CVE
- CVE-2023-34470
- Published
- Sep 12, 2023
- Updated
- Sep 26, 2024
- Vendor
- American Megatrends International
- Product
- Aptio V
- Classifications
- CWE-284, CAPEC-551
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 12, 2023CVE publishedPublication date reported by the CVE source.
- Sep 26, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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- Affected versionversion=*
What conditions does exploitation require?
What is affected?
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.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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