CVE-2023-54321 – A null pointer dereference vulnerability in the... (How to Fix)

Q: What is the severity of CVE-2023-54321?

CVE-2023-54321 has a CVSS score of 5.5 (MEDIUM). A null pointer dereference vulnerability in the Linux kernel's device_add() function can cause kernel crashes when device registration fails during fault injection or error conditions. This affects Linux systems with specific hardware drivers that trigger the error path during device initialization. The vulnerability leads to denial of service but not privilege escalation.

📋 TL;DR

A null pointer dereference vulnerability in the Linux kernel's device_add() function can cause kernel crashes when device registration fails during fault injection or error conditions. This affects Linux systems with specific hardware drivers that trigger the error path during device initialization. The vulnerability leads to denial of service but not privilege escalation.

💻 Affected Systems

Products:

Linux kernel

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

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires specific hardware drivers (like w1/ds2482) and error conditions during device registration to trigger.

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and complete denial of service, requiring physical or remote reboot.

🟠

Likely Case

System instability or crash when specific hardware devices fail to initialize properly, affecting availability.

🟢

If Mitigated

Minimal impact with proper monitoring and redundancy; single system crashes in clustered environments.

🌐 Internet-Facing: LOW - Requires local access or specific hardware interaction; not directly exploitable over network.

🏢 Internal Only: MEDIUM - Could affect critical systems during hardware failures or maintenance, but requires specific conditions.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: HIGH - Requires specific hardware and error conditions to trigger

Discovered during fault injection testing; exploitation requires ability to trigger device registration failures.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 17982304806c5c10924e73f7ca5556e0d7378452, 2c59650d078b1b3f1ea50d5f8ee9fcc537dc02d3, 7cf515bf9e8c2908dc170ecf2df117162a16c9c5, 97aa8fb74bbe9aaf4ed5962a784f73b071bd16bf, f6837f34a34973ef6600c08195ed300e24e97317

Vendor Advisory: https://git.kernel.org/stable/c/17982304806c5c10924e73f7ca5556e0d7378452

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing fix commits. 2. Check distribution-specific security advisories. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable affected hardware modules

linux

Blacklist or disable specific hardware drivers that trigger the vulnerability

echo 'blacklist ds2482' >> /etc/modprobe.d/blacklist.conf
echo 'blacklist wire' >> /etc/modprobe.d/blacklist.conf

🧯 If You Can't Patch

Implement system monitoring for kernel panics and crashes
Ensure redundancy for critical systems to maintain availability during crashes

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if specific hardware modules (ds2482, wire) are loaded: lsmod | grep -E 'ds2482|wire'

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits: uname -r and check distribution patch notes

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
NULL pointer dereference in kernel logs
System crash/reboot events

Network Indicators:

Unplanned system downtime
Service unavailability

SIEM Query:

source="kernel" AND "NULL pointer dereference" OR "kernel panic"

📊 Metadata

CVE ID: CVE-2023-54321

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-476

EPSS Score: 0.05% exploit probability (13.5th percentile)

Published: December 30, 2025

Last Updated: February 26, 2026

🔗 References

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🔗 Related Vulnerabilities

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