CVE-2023-53612 – A NULL pointer dereference vulnerability in the... (How to Fix)

Q: What is the severity of CVE-2023-53612?

CVE-2023-53612 has a CVSS score of 5.5 (MEDIUM). A NULL pointer dereference vulnerability in the Linux kernel's coretemp hardware monitoring driver could cause kernel panics or system crashes when CPU hotplug operations occur with drivers_autoprobe disabled. This affects Linux systems using the coretemp driver for CPU temperature monitoring, particularly those with dynamic CPU hotplug capabilities.

📋 TL;DR

A NULL pointer dereference vulnerability in the Linux kernel's coretemp hardware monitoring driver could cause kernel panics or system crashes when CPU hotplug operations occur with drivers_autoprobe disabled. This affects Linux systems using the coretemp driver for CPU temperature monitoring, particularly those with dynamic CPU hotplug capabilities.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE description, but references indicate stable kernel patches.

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires coretemp driver to be loaded and systems with CPU hotplug capabilities. More likely on servers with dynamic CPU management.

⚠️ Risk & Real-World Impact

🔴

Worst Case

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

🟠

Likely Case

System instability or crash during CPU hotplug operations, particularly on systems with dynamic CPU management.

🟢

If Mitigated

No impact if the vulnerable code path isn't triggered or if proper kernel hardening is in place.

🌐 Internet-Facing: LOW - Requires local access or ability to trigger CPU hotplug operations.

🏢 Internal Only: MEDIUM - Could be triggered by legitimate system management operations or malicious local users.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires ability to trigger CPU hotplug events or manipulate platform bus configuration.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patched in stable kernel commits referenced in CVE

Vendor Advisory: https://git.kernel.org/stable/c/4000384684f612b3645a944f6acde0e65ac370b8

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable coretemp module

linux

Prevent loading of vulnerable coretemp driver

echo 'blacklist coretemp' >> /etc/modprobe.d/blacklist.conf
rmmod coretemp

Disable CPU hotplug

linux

Prevent triggering of vulnerable code path

echo 0 > /sys/devices/system/cpu/cpuX/online (for each CPU)

🧯 If You Can't Patch

Ensure drivers_autoprobe is enabled for platform bus to avoid NULL dereference
Monitor system logs for coretemp-related crashes and have recovery procedures ready

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if coretemp module is loaded: lsmod | grep coretemp && uname -r

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated and check dmesg for coretemp-related errors after CPU hotplug operations

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
NULL pointer dereference in coretemp driver
CPU hotplug related crashes

Network Indicators:

None - local vulnerability

SIEM Query:

source="kernel" AND ("coretemp" OR "NULL pointer dereference")

📊 Metadata

CVE ID: CVE-2023-53612

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

Published: October 4, 2025

Last Updated: February 5, 2026

🤖 AI-assisted analysis, reviewed for accuracy

🔗 References

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