CVE-2023-52509 – This is a use-after-free vulnerability in the L... (How to Fix)

Q: What is the severity of CVE-2023-52509?

CVE-2023-52509 has a CVSS score of 7.8 (HIGH). This is a use-after-free vulnerability in the Linux kernel's RAVB Ethernet driver that could allow local attackers to crash the system or potentially execute arbitrary code. It affects systems using the Renesas Ethernet AVB driver. The vulnerability occurs when the driver fails to properly synchronize work cancellation during network interface shutdown.

📋 TL;DR

This is a use-after-free vulnerability in the Linux kernel's RAVB Ethernet driver that could allow local attackers to crash the system or potentially execute arbitrary code. It affects systems using the Renesas Ethernet AVB driver. The vulnerability occurs when the driver fails to properly synchronize work cancellation during network interface shutdown.

💻 Affected Systems

Products:

Linux kernel with RAVB Ethernet driver

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

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems using the Renesas Ethernet AVB driver (typically embedded/SoC systems)

📦 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...

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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

Local privilege escalation leading to kernel compromise and full system control

🟠

Likely Case

Kernel panic or system crash causing denial of service

🟢

If Mitigated

No impact if patched or workaround applied

🌐 Internet-Facing: LOW - Requires local access to the system

🏢 Internal Only: MEDIUM - Local attackers on affected systems could cause crashes

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and ability to trigger network timeout conditions

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 105abd68ad8f781985113aee2e92e0702b133705 and related stable backports

Vendor Advisory: https://git.kernel.org/stable/c/105abd68ad8f781985113aee2e92e0702b133705

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable RAVB driver if not needed

linux

Remove or blacklist the RAVB driver module if the hardware is not being used

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

🧯 If You Can't Patch

Restrict local user access to prevent exploitation
Monitor system logs for kernel panics or crashes related to network timeouts

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if RAVB driver is loaded: lsmod | grep ravb && uname -r

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated and check if RAVB module loads without issues

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
Use-after-free warnings in dmesg
Network interface errors

Network Indicators:

Sudden network interface failures on affected hardware

SIEM Query:

source="kernel" AND ("use-after-free" OR "ravb" OR "tx_timeout")

📊 Metadata

CVE ID: CVE-2023-52509

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-416

Published: March 2, 2024

Last Updated: December 11, 2024

🔗 References

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🔗 Related Vulnerabilities

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