CVE-2023-53305 – This CVE describes a use-after-free vulnerabili... (How to Fix)

Q: What is the severity of CVE-2023-53305?

CVE-2023-53305 has a CVSS score of 7.8 (HIGH). This CVE describes a use-after-free vulnerability in the Linux kernel's Bluetooth L2CAP implementation. Attackers could potentially exploit this to execute arbitrary code or cause denial of service on affected systems. Any Linux system with Bluetooth enabled and running vulnerable kernel versions is affected.

📋 TL;DR

This CVE describes a use-after-free vulnerability in the Linux kernel's Bluetooth L2CAP implementation. Attackers could potentially exploit this to execute arbitrary code or cause denial of service on affected systems. Any Linux system with Bluetooth enabled and running vulnerable kernel versions is affected.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific vulnerable versions not explicitly stated in CVE, but patches available for multiple stable branches

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only vulnerable when Bluetooth subsystem is enabled and in use

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution with kernel privileges leading to complete system compromise

🟠

Likely Case

Kernel panic or system crash causing denial of service

🟢

If Mitigated

Limited impact if Bluetooth is disabled or proper network segmentation is in place

🌐 Internet-Facing: LOW (requires Bluetooth proximity or specific network access)

🏢 Internal Only: MEDIUM (requires attacker to be within Bluetooth range or have internal network access)

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires Bluetooth access and knowledge of kernel internals

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Multiple stable kernel versions with fixes (see git commits in references)

Vendor Advisory: https://git.kernel.org/stable/c/149daab45922ab1ac7f0cbeacab7251a46bf5e63

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version 2. Reboot system 3. Verify kernel version after reboot

🔧 Temporary Workarounds

Disable Bluetooth

linux

Completely disable Bluetooth subsystem to eliminate attack surface

systemctl stop bluetooth
systemctl disable bluetooth
rfkill block bluetooth

Disable L2CAP protocol

linux

Block L2CAP protocol if Bluetooth must remain enabled

echo 0 > /sys/kernel/debug/bluetooth/l2cap/enable

🧯 If You Can't Patch

Disable Bluetooth completely on all affected systems
Implement network segmentation to isolate Bluetooth traffic

🔍 How to Verify

Check if Vulnerable:

Check kernel version and compare with patched versions in git commits

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version matches patched version and Bluetooth functions normally

📡 Detection & Monitoring

Log Indicators:

Kernel panic logs
Bluetooth subsystem crashes in dmesg
L2CAP protocol errors

Network Indicators:

Unusual Bluetooth connection attempts
Malformed L2CAP packets

SIEM Query:

source="kernel" AND ("panic" OR "oops" OR "L2CAP" OR "use-after-free")

📊 Metadata

CVE ID: CVE-2023-53305

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

EPSS Score: 0.01% exploit probability (1th percentile)

Published: September 16, 2025

Last Updated: January 14, 2026

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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