SMM escalation via StorageSecurityCommandDxe out-of-bounds write
Published Feb 2, 2022 · Updated Aug 11, 2026
Out-of-bounds write in InsydeH2O StorageSecurityCommandDxe allows local users to escalate from ring 0 into System Management Mode. The driver writes fixed or predictable data beyond its intended bounds into protected SMRAM, corrupting SMM memory. Exploitation requires high-privilege local execution of untrusted code and grants arbitrary code execution in ring -2, beyond operating-system controls.
Summary
What happened
Out-of-bounds write in InsydeH2O StorageSecurityCommandDxe allows local users to escalate from ring 0 into System Management Mode. The driver writes fixed or predictable data beyond its intended bounds into protected SMRAM, corrupting SMM memory. Exploitation requires high-privilege local execution of untrusted code and grants arbitrary code execution in ring -2, beyond operating-system controls.
The record
- CVE
- CVE-2021-43522
- Published
- Feb 2, 2022
- Updated
- Aug 11, 2026
- Vendor
- Siemens
- Product
- SIMATIC IPC477E PRO
- Classifications
- CWE-787, T1542.001
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Feb 2, 2022CVE publishedPublication date reported by the CVE source.
- Aug 11, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <V21.01.17
What conditions does exploitation require?
What is affected?
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
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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