CVE-2023-53386
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Linux kernel's Bluetooth subsystem. When clearing cryptographic keys, the kernel can access memory after it has been freed, potentially allowing local attackers to execute arbitrary code or cause denial of service. This affects systems with Bluetooth functionality enabled.
💻 Affected Systems
- Linux kernel
📦 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
Local privilege escalation to kernel-level access, allowing complete system compromise and potential persistence.
Likely Case
Kernel panic or system crash leading to denial of service, with potential for limited code execution.
If Mitigated
Minimal impact if Bluetooth is disabled or proper access controls prevent local attackers from triggering the vulnerability.
🎯 Exploit Status
Requires local access and ability to interact with Bluetooth subsystem. Similar to previously fixed CVE-2023-XXXXX patterns.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 35cc42f04bc49f0656f6840cb7451b3df6049649 through da19f35868dfbecfff4f81166c054d2656cb1be4
Vendor Advisory: https://git.kernel.org/stable/c/35cc42f04bc49f0656f6840cb7451b3df6049649
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable Bluetooth
linuxDisable Bluetooth functionality to prevent exploitation
sudo systemctl stop bluetooth
sudo systemctl disable bluetooth
sudo rfkill block bluetooth
Restrict Bluetooth access
linuxUse access controls to prevent unauthorized users from accessing Bluetooth interfaces
sudo chmod 600 /sys/class/bluetooth/*
sudo setfacl -m u:root:rwx /sys/class/bluetooth/*
🧯 If You Can't Patch
- Disable Bluetooth functionality completely on affected systems
- Implement strict access controls to prevent local users from interacting with Bluetooth subsystem
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions from distribution vendor. Check if Bluetooth is active: 'systemctl status bluetooth' or 'rfkill list'Check Version:
uname -rVerify Fix Applied:
Verify kernel version after update matches patched version from vendor. Check that Bluetooth functionality still works if needed.📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages related to Bluetooth
- System crashes when Bluetooth keys are cleared
- dmesg errors mentioning use-after-free in Bluetooth code
Network Indicators:
- Unusual Bluetooth connection attempts from local users
- Multiple Bluetooth service restarts
SIEM Query:
source="kernel" AND ("Bluetooth" AND ("use-after-free" OR "oops" OR "panic"))🔗 References
- https://git.kernel.org/stable/c/35cc42f04bc49f0656f6840cb7451b3df6049649
- https://git.kernel.org/stable/c/3673952cf0c6cf81b06c66a0b788abeeb02ff3ae
- https://git.kernel.org/stable/c/942d8cefb022f384d5424f8b90c7878f3f93726f
- https://git.kernel.org/stable/c/94617b736c25091b60e514e2e7aeafcbbee6b700
- https://git.kernel.org/stable/c/da19f35868dfbecfff4f81166c054d2656cb1be4
- https://git.kernel.org/stable/c/e87da6a0ac6e631454e7da53a76aa9fe44aaa5dd
