Unsigned code execution via unchecked NTFS sector writes
Published Oct 25, 2023 · Updated Jul 21, 2026
Out-of-bounds write in the GRUB2 NTFS driver in Red Hat Enterprise Linux 7 through 9 allows local users to execute unsigned code. The find_attr path reuses an NTFS $ATTRIBUTE_LIST buffer for sector numbers and writes at offsets 0x10 and 0x14 without ensuring that 24 bytes remain. Exploitation requires high local privileges and a crafted, highly fragmented NTFS image; Red Hat notes that its signed GRUB2 image omits the NTFS module.
Summary
What happened
Out-of-bounds write in the GRUB2 NTFS driver in Red Hat Enterprise Linux 7 through 9 allows local users to execute unsigned code. The find_attr path reuses an NTFS $ATTRIBUTE_LIST buffer for sector numbers and writes at offsets 0x10 and 0x14 without ensuring that 24 bytes remain. Exploitation requires high local privileges and a crafted, highly fragmented NTFS image; Red Hat notes that its signed GRUB2 image omits the NTFS module.
The record
- CVE
- CVE-2023-4692
- Published
- Oct 25, 2023
- Updated
- Jul 21, 2026
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8
- Classifications
- CWE-787, CWE-122, T1542.003
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Oct 25, 2023CVE publishedPublication date reported by the CVE source.
- Jul 21, 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?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
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
- GRUB2 NTFS heap-overflow demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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