GRUB2 OOB Write in NTFS Driver Enables UEFI Heap Corruption & Secure Boot Bypass
CVE-2023-4692 Published on October 25, 2023
Grub2: out-of-bounds write at fs/ntfs.c may lead to unsigned code execution
An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. This issue may allow an attacker to present a specially crafted NTFS filesystem image, leading to grub's heap metadata corruption. In some circumstances, the attack may also corrupt the UEFI firmware heap metadata. As a result, arbitrary code execution and secure boot protection bypass may be achieved.
Vulnerability Analysis
CVE-2023-4692 is exploitable with local system access, and requires user privileges. This vulnerability is consided to have a high level of attack complexity. Public availability of a proof of concept (POC) exploit exists for CVE-2023-4692. The potential impact of an exploit of this vulnerability is considered to be very high.
Timeline
Reported to Red Hat.
Made public. 33 days later.
Weakness Type
Heap-based Buffer Overflow
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
Products Associated with CVE-2023-4692
You can be notified by email with stack.watch whenever vulnerabilities like CVE-2023-4692 are published in these products:
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.