SMM code execution via unchecked destination pointer
Published Dec 10, 2021 · Updated Sep 16, 2024
Arbitrary code execution in AMD AGESA on selected 2016–2019 client and embedded APUs allows local users to run code in SMM. SMI handler 0xEF passes attacker-controlled ArgsStruct pointers to SmmGetVariable without validating RSI, inner pointers, or the destination buffer, permitting an arbitrary write into SMRAM. Administrative or physical access is required; successful exploitation bypasses operating-system, kernel, hypervisor, and firmware security boundaries.
Summary
What happened
Arbitrary code execution in AMD AGESA on selected 2016–2019 client and embedded APUs allows local users to run code in SMM. SMI handler 0xEF passes attacker-controlled ArgsStruct pointers to SmmGetVariable without validating RSI, inner pointers, or the destination buffer, permitting an arbitrary write into SMRAM. Administrative or physical access is required; successful exploitation bypasses operating-system, kernel, hypervisor, and firmware security boundaries.
The record
- CVE
- CVE-2020-12890
- Published
- Dec 10, 2021
- Updated
- Sep 16, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- T1068
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Dec 10, 2021CVE publishedPublication date reported by the CVE source.
- Sep 16, 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?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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
- Attacking the Golden Ring on AMD Mini-PC proof of conceptfunctional · demonstrated
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Technologies
Your stack
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Your stack
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