SMM code execution via unchecked function pointer
Published Mar 11, 2022 · Updated Sep 17, 2024
Improper input validation in Dell Client Platform BIOS before 1.16 allows local users to execute arbitrary code in SMM through an SMI. The USBRT software-SMI handler accepts an attacker-controlled structure, derives a table pointer from unchecked fields, and passes it to Invoke. Ring 0 access is required; successful exploitation gains ring -2 execution and can modify protected firmware for persistence across OS reinstallations.
Summary
What happened
Improper input validation in Dell Client Platform BIOS before 1.16 allows local users to execute arbitrary code in SMM through an SMI. The USBRT software-SMI handler accepts an attacker-controlled structure, derives a table pointer from unchecked fields, and passes it to Invoke. Ring 0 access is required; successful exploitation gains ring -2 execution and can modify protected firmware for persistence across OS reinstallations.
The record
- CVE
- CVE-2022-24420
- Published
- Mar 11, 2022
- Updated
- Sep 17, 2024
- Vendor
- Dell
- Product
- Dell Client Platform BIOS
- Classifications
- CWE-119, T1542.001, T1068
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Mar 11, 2022CVE publishedPublication date reported by the CVE source.
- Sep 17, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <1.16
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.
Weakness, pattern, technique
Public exploit references
- USBRT SMM handler exploitation pseudocodeproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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