CVE-2023-53019 – This vulnerability in the Linux kernel's MDIO s... (How to Fix)

Q: What is the severity of CVE-2023-53019?

CVE-2023-53019 has a CVSS score of 7.8 (HIGH). This vulnerability in the Linux kernel's MDIO subsystem allows out-of-bounds memory access when invalid PHY addresses are passed to the mdiobus_get_phy() function. Attackers could potentially crash the system or execute arbitrary code by exploiting this memory corruption. All Linux systems using the affected kernel versions with network interfaces that utilize MDIO bus communication are affected.

📋 TL;DR

This vulnerability in the Linux kernel's MDIO subsystem allows out-of-bounds memory access when invalid PHY addresses are passed to the mdiobus_get_phy() function. Attackers could potentially crash the system or execute arbitrary code by exploiting this memory corruption. All Linux systems using the affected kernel versions with network interfaces that utilize MDIO bus communication are affected.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE, but patches exist in stable kernel trees. Likely affects multiple kernel versions before the fix.

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires systems using MDIO bus for network PHY management. Common in embedded systems, routers, and servers with certain network hardware.

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to denial of service, or potential privilege escalation to kernel-level code execution allowing complete system compromise.

🟠

Likely Case

System crash or kernel panic causing denial of service, potentially requiring physical or remote console access to reboot.

🟢

If Mitigated

System remains stable with proper input validation preventing invalid PHY address access.

🌐 Internet-Facing: MEDIUM - Requires network access to vulnerable network interfaces, but exploitation may be complex and require specific conditions.

🏢 Internal Only: MEDIUM - Internal attackers with network access could potentially trigger the vulnerability, though exploitation complexity remains.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires ability to trigger the vulnerable function with invalid PHY addresses, which may require specific hardware/driver conditions.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patches available in stable kernel trees (commits referenced in CVE)

Vendor Advisory: https://git.kernel.org/stable/c/1d80c259dfbadefa61b7ea334dfce5cb57f8c72f

Restart Required: Yes

Instructions:

1. Update to a patched kernel version from your distribution's repositories. 2. Reboot the system to load the new kernel. 3. Verify the fix is applied by checking kernel version.

🔧 Temporary Workarounds

Disable vulnerable network interfaces

all

Temporarily disable network interfaces that use MDIO bus if not critical

ip link set <interface> down

🧯 If You Can't Patch

Implement network segmentation to isolate systems with vulnerable kernels
Monitor for system crashes or kernel panics and maintain current backups

🔍 How to Verify

Check if Vulnerable:

Check kernel version against your distribution's security advisories. Vulnerable if using unpatched kernel with MDIO functionality.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version after update matches patched version from distribution security advisory.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/messages or dmesg
System crash reports
Network interface errors

Network Indicators:

Unexpected network interface resets
Increased network errors on MDIO-capable interfaces

SIEM Query:

source="kernel" AND ("panic" OR "Oops" OR "general protection fault") AND process="kernel"

📊 Metadata

CVE ID: CVE-2023-53019

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-129

EPSS Score: 0.06% exploit probability (19.9th percentile)

Published: March 27, 2025

Last Updated: October 30, 2025

🔗 References

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