Local privilege escalation via shared GetVariable size
Published Sep 22, 2022 · Updated Jul 9, 2026
Stack-based buffer overflow in Acer UEFI firmware allows local users to execute code in DXE via crafted NVRAM variables. TcgPlatformSetupPolicy reuses a DataSize value enlarged by the first GetVariable call when a second call writes into a smaller stack buffer. Low-privileged local access that can set the two variables enables control-flow hijacking and persistent firmware-level code execution across boots.
Summary
What happened
Stack-based buffer overflow in Acer UEFI firmware allows local users to execute code in DXE via crafted NVRAM variables. TcgPlatformSetupPolicy reuses a DataSize value enlarged by the first GetVariable call when a second call writes into a smaller stack buffer. Low-privileged local access that can set the two variables enables control-flow hijacking and persistent firmware-level code execution across boots.
The record
- CVE
- CVE-2022-30426
- Published
- Sep 22, 2022
- Updated
- Jul 9, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-787, T1542.001
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 22, 2022CVE publishedPublication date reported by the CVE source.
- Jul 9, 2026Record 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.
Public exploit references
- UEFI NVRAM variable proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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