CVE-2023-52821 – This CVE describes a null pointer dereference v... (How to Fix)

Q: What is the severity of CVE-2023-52821?

CVE-2023-52821 has a CVSS score of 5.5 (MEDIUM). This CVE describes a null pointer dereference vulnerability in the Linux kernel's DRM panel driver. If exploited, it could cause a kernel panic or system crash, affecting systems running vulnerable Linux kernel versions with the versatile_panel driver loaded. The vulnerability requires local access to trigger.

📋 TL;DR

This CVE describes a null pointer dereference vulnerability in the Linux kernel's DRM panel driver. If exploited, it could cause a kernel panic or system crash, affecting systems running vulnerable Linux kernel versions with the versatile_panel driver loaded. The vulnerability requires local access to trigger.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific vulnerable kernel versions referenced in the git commits (need to check which kernel releases contain these commits)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if the versatile_panel DRM driver is loaded and used. Many systems may not have this driver enabled.

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to denial of service (system crash), potentially allowing local privilege escalation if combined with other vulnerabilities.

🟠

Likely Case

Local denial of service through kernel panic or system crash when the versatile_panel driver is used.

🟢

If Mitigated

No impact if the vulnerable driver is not loaded or system is patched.

🌐 Internet-Facing: LOW - Requires local access to trigger, not remotely exploitable.

🏢 Internal Only: MEDIUM - Local users or processes could crash the system, but requires specific driver usage.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and specific conditions to trigger the null pointer dereference. No public exploit code identified.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing the fix commits: 2381f6b628b3214f07375e0adf5ce17093c31190, 4fa930ba046d20fc1899770396ee11e905fa96e4, 79813cd59398015867d51e6d7dcc14d287d4c402, 8a9dd36fcb4f3906982b82593393578db4479992, 924e5814d1f84e6fa5cb19c6eceb69f066225229

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

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. Reboot system to load new kernel. 3. Check that versatile_panel driver is not causing issues.

🔧 Temporary Workarounds

Disable versatile_panel driver

linux

Prevent loading of the vulnerable driver module

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

🧯 If You Can't Patch

Ensure versatile_panel driver is not loaded (check with lsmod)
Restrict local user access to systems where this driver might be used

🔍 How to Verify

Check if Vulnerable:

Check if versatile_panel driver is loaded: lsmod | grep versatile_panel. If loaded and kernel version is vulnerable, system is at risk.

Check Version:

uname -r

Verify Fix Applied:

Check kernel version is patched and versatile_panel driver loads without issues. Monitor dmesg for null pointer errors.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in dmesg or syslog
NULL pointer dereference errors mentioning versatile_panel

Network Indicators:

None - local vulnerability only

SIEM Query:

source="kernel" AND "NULL pointer dereference" AND "versatile_panel"

📊 Metadata

CVE ID: CVE-2023-52821

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: May 21, 2024

Last Updated: November 21, 2024

🔗 References

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🔗 Related Vulnerabilities

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