CVE-2024-27407: Linux Kernel Buffer Overflow Vulnerability

CVE-2024-27407 Overview

CVE-2024-27407 is a buffer overflow vulnerability in the Linux kernel's NTFS3 filesystem driver. The flaw resides in the mi_enum_attr() function within fs/ntfs3, where an insufficient overflow check allowed out-of-bounds memory access when parsing NTFS metadata. A local attacker who can mount or supply a crafted NTFS filesystem image can trigger memory corruption, leading to confidentiality, integrity, and availability impact on the host system. The vulnerability is tracked under CWE-120: Buffer Copy without Checking Size of Input. Linux kernel maintainers have resolved the issue via upstream commits.

Critical Impact
Local attackers exploiting crafted NTFS images can achieve memory corruption in kernel context, potentially resulting in privilege escalation or system compromise.

Affected Products

Linux Kernel (multiple stable branches prior to fix)
Linux Kernel 6.8-rc1, 6.8-rc2, 6.8-rc3
Debian LTS distributions shipping affected kernel versions

Discovery Timeline

2024-05-17 - CVE-2024-27407 published to NVD
2026-08-04 - Last updated in NVD database

Technical Details for CVE-2024-27407

Vulnerability Analysis

The vulnerability exists in the NTFS3 filesystem driver, which provides read/write support for Microsoft NTFS volumes in the Linux kernel. The mi_enum_attr() function iterates over MFT (Master File Table) record attributes. Prior to the fix, the function's overflow check did not correctly validate attribute size and offset fields against record boundaries.

When an attacker supplies an NTFS image containing malformed attribute headers, the loop can read or process memory beyond the intended MFT record buffer. Because the attack requires local access and user interaction (mounting or opening a crafted filesystem), remote exploitation is not viable. However, in environments where users can attach removable media or containers can mount user-supplied filesystems, this significantly widens the exposure.

Root Cause

The root cause is inadequate bounds validation in mi_enum_attr() when computing the next attribute offset. The original check failed to account for arithmetic overflow when combining attribute length values with the current position, allowing crafted metadata to bypass the boundary test and reference memory outside the intended record.

Attack Vector

Exploitation requires local access with user interaction. An attacker crafts a malicious NTFS image and induces a victim (or automount subsystem) to mount it. When the kernel parses the MFT, the flawed overflow check permits out-of-bounds reads or subsequent memory corruption. Vulnerability details are described in the upstream kernel commit.

No verified public exploit code is available. The vulnerability mechanism is described in prose only; refer to the linked commits for the specific patched logic in mi_enum_attr().

Detection Methods for CVE-2024-27407

Indicators of Compromise

Unexpected kernel oops or panic messages referencing ntfs3 or mi_enum_attr in dmesg or /var/log/kern.log
Mount attempts of NTFS images from untrusted sources, especially via USB or loopback devices
Kernel KASAN or slab-out-of-bounds warnings tied to NTFS3 code paths

Detection Strategies

Inventory kernel versions across Linux endpoints and compare against fixed commits to identify unpatched hosts
Monitor mount syscalls with type=ntfs3 originating from non-administrative users or containerized workloads
Alert on kernel crash telemetry that references the NTFS3 module or MFT parsing routines

Monitoring Recommendations

Collect kernel logs centrally and index them for search over messages containing ntfs3, BUG:, or KASAN
Track removable media insertion events and correlate with subsequent kernel warnings
Enable auditd rules for mount and umount operations to establish a baseline and detect anomalies

How to Mitigate CVE-2024-27407

Immediate Actions Required

Apply the latest stable kernel update from your distribution that incorporates the upstream fix commits
Restrict mounting of untrusted NTFS filesystems to privileged users only
Disable automount services for removable media on servers and shared systems where NTFS support is not required

Patch Information

The fix is available in the mainline Linux kernel via commits 1c0a95d99b1b, 652cfeb43d6b, 8c77398c7261, and e99faa973596. Debian users should consult the Debian LTS Announcement for backported package versions. Enterprise distributions including Red Hat, SUSE, and Ubuntu have shipped updated kernel packages; apply vendor updates through the standard package manager.

Workarounds

Blacklist the ntfs3 kernel module on systems that do not require NTFS support using /etc/modprobe.d/
Remove or restrict SUID mount helpers that permit unprivileged NTFS mounting
In containerized environments, drop the CAP_SYS_ADMIN capability to prevent user-controlled filesystem mounting

bash

# Blacklist the ntfs3 module until patching is complete
echo "blacklist ntfs3" | sudo tee /etc/modprobe.d/blacklist-ntfs3.conf
sudo update-initramfs -u

# Verify installed kernel version against fixed builds
uname -r
apt list --installed 2>/dev/null | grep linux-image