CVE-2024-46676 – A division-by-zero vulnerability in the Linux k... (How to Fix)

Q: What is the severity of CVE-2024-46676?

CVE-2024-46676 has a CVSS score of 5.5 (MEDIUM). A division-by-zero vulnerability in the Linux kernel's NFC subsystem allows local attackers to cause a kernel panic (denial of service) by sending specially crafted Netlink messages. This affects systems with NFC hardware using the pn533 driver. The vulnerability requires local access or ability to send Netlink messages to the NFC subsystem.

📋 TL;DR

A division-by-zero vulnerability in the Linux kernel's NFC subsystem allows local attackers to cause a kernel panic (denial of service) by sending specially crafted Netlink messages. This affects systems with NFC hardware using the pn533 driver. The vulnerability requires local access or ability to send Netlink messages to the NFC subsystem.

💻 Affected Systems

Products:

Linux kernel

Versions: Versions before the fix commits (specific versions vary by distribution)

Operating Systems: Linux distributions with NFC support and pn533 driver

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems with NFC hardware using the pn533 driver. Requires NFC subsystem to be enabled and accessible.

📦 What is this software?

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, potentially requiring physical reboot.

🟠

Likely Case

Local denial of service through kernel panic, disrupting NFC functionality and potentially affecting system stability.

🟢

If Mitigated

Minimal impact if proper access controls prevent unauthorized users from sending Netlink messages to the NFC subsystem.

🌐 Internet-Facing: LOW - This is a local vulnerability requiring access to send Netlink messages, not directly exploitable over the internet.

🏢 Internal Only: MEDIUM - Malicious local users or compromised processes with appropriate permissions could exploit this to crash the system.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: LOW - Simple Netlink message with specific protocol values triggers the issue.

Exploitation requires ability to send NFC_CMD_START_POLL Netlink messages with im_protocols=1 and tm_protocols=0.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 56ad559cf6d87f250a8d203b555dfc3716afa946, 64513d0e546a1f19e390f7e5eba3872bfcbdacf5, 7535db0624a2dede374c42040808ad9a9101d723, 7ecd3dd4f8eecd3309432156ccfe24768e009ec4, 8ddaea033de051ed61b39f6b69ad54a411172b33

Vendor Advisory: https://git.kernel.org/stable/c/56ad559cf6d87f250a8d203b555dfc3716afa946

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. Check your distribution's security advisories for specific patched versions. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable NFC subsystem

linux

Remove or blacklist NFC modules to prevent access to vulnerable code path.

echo 'blacklist nfc' >> /etc/modprobe.d/blacklist-nfc.conf
rmmod nfc pn533

Restrict Netlink access

linux

Use SELinux/AppArmor or capabilities to restrict which users/processes can send NFC Netlink messages.

🧯 If You Can't Patch

Disable NFC functionality if not required
Implement strict access controls to prevent unauthorized users from interacting with NFC subsystem

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if NFC modules are loaded: 'lsmod | grep -E "(nfc|pn533)"' and 'uname -r'

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits or is newer than vulnerable versions. Check distribution security advisories.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
NFC subsystem errors
Division by zero kernel oops

SIEM Query:

source="kernel" AND ("division by zero" OR "kernel panic" OR "nfc")

📊 Metadata

CVE ID: CVE-2024-46676

CVSS v3 Score: 5.5 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-369

Published: September 13, 2024

Last Updated: November 3, 2025

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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