CVE-2023-4693 Grub2: out-of-bounds read at fs/ntfs.c
A physically present attacker can leak sensitive memory or EFI variables via a crafted NTFS image in the GRUB2 bootloader.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-4693?
CVE-2023-4693 is a medium-severity vulnerability in Redhat Enterprise Linux, published on 25 Oct 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An out-of-bounds read flaw was found on grub2's NTFS filesystem driver. This issue may allow a physically present attacker to present a specially crafted NTFS file system image to read arbitrary memory locations. A successful attack allows sensitive data cached in memory or EFI variable values to be leaked, presenting a high Confidentiality risk.
Weakness: CWE-125
Which versions are affected by CVE-2023-4693?
It affects 2 products.
Products include Gnu Grub2, Redhat Enterprise Linux.
How do I fix CVE-2023-4693?
Apply the vendor's patch.
Is CVE-2023-4693 being exploited?
There is no known exploitation of CVE-2023-4693 in the wild and no public exploit code.
Other vulnerabilities in Redhat Enterprise Linux
- CVE-2024-56737 Memory corruption in GRUB2
- CVE-2022-28733 Integer underflow in grub_net_recv_ip4_packets
- CVE-2022-28734 Out-of-bounds write when handling split HTTP headers
- CVE-2025-61662 Grub2: missing unregister call for gettext command may lead to use-after-free
- CVE-2024-45782 Grub2: fs/hfs: strcpy() using the volume name (fs/hfs.c:382)
Sources
Also known as AZL-31685, AZL-34794, BELL-CVE-2023-4693, CLSA-2024-1724433427, CLSA-2024-1724434789, CLSA-2024-1724871398 and 3 more.