SYSTEM privilege escalation via unchecked FSCTL buffer
Published Apr 9, 2024 · Updated May 3, 2025
Heap-based buffer overflow in Microsoft Windows CSC Service allows local users to execute code with SYSTEM privileges via a crafted FSCTL request. CscDevFcbXXXControlFile trusts a METHOD_NEITHER input pointer for FSCTL 0x001401a3 and writes through it without first validating its length or writability. Low-privileged local access is sufficient to corrupt KTHREAD PreviousMode, obtain kernel read/write access, and steal a SYSTEM token.
Summary
What happened
Heap-based buffer overflow in Microsoft Windows CSC Service allows local users to execute code with SYSTEM privileges via a crafted FSCTL request. CscDevFcbXXXControlFile trusts a METHOD_NEITHER input pointer for FSCTL 0x001401a3 and writes through it without first validating its length or writability. Low-privileged local access is sufficient to corrupt KTHREAD PreviousMode, obtain kernel read/write access, and steal a SYSTEM token.
The record
- CVE
- CVE-2024-26229
- Published
- Apr 9, 2024
- Updated
- May 3, 2025
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-122, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 9, 2024CVE publishedPublication date reported by the CVE source.
- May 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=10.0.10240.0 <10.0.10240.20596
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.
Weakness, pattern, technique
Public exploit references
- CVE-2024-26229 BOFfunctional · demonstrated
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Technologies
Your stack
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Your stack
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