CVE-2023-44431
📋 TL;DR
This vulnerability allows attackers within Bluetooth range to execute arbitrary code with root privileges on systems running vulnerable BlueZ installations. The flaw exists in the AVRCP protocol handling where improper length validation leads to stack-based buffer overflow. User interaction is required as the target must connect to a malicious Bluetooth device.
💻 Affected Systems
- BlueZ (Linux Bluetooth protocol stack)
📦 What is this software?
Bluez by Bluez
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with root-level code execution, allowing complete control over the affected device, data theft, and lateral movement within the network.
Likely Case
Remote code execution with root privileges leading to system compromise, but requiring physical proximity and user interaction to connect to malicious Bluetooth device.
If Mitigated
Limited impact if Bluetooth is disabled, devices are not paired with unknown devices, or proper network segmentation isolates Bluetooth traffic.
🎯 Exploit Status
Requires attacker to be within Bluetooth range and user to connect to malicious device. Exploit requires crafting malicious AVRCP packets.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check distribution-specific security updates (e.g., BlueZ 5.66 or later with backported fixes)
Vendor Advisory: https://www.zerodayinitiative.com/advisories/ZDI-23-1900/
Restart Required: Yes
Instructions:
1. Update BlueZ package via distribution package manager. 2. For Ubuntu/Debian: sudo apt update && sudo apt upgrade bluez. 3. For Fedora/RHEL: sudo dnf update bluez. 4. Restart Bluetooth service or reboot system.
🔧 Temporary Workarounds
Disable Bluetooth
linuxCompletely disable Bluetooth to prevent exploitation
sudo systemctl stop bluetooth
sudo systemctl disable bluetooth
Restrict Bluetooth Pairing
linuxConfigure Bluetooth to only pair with trusted devices
sudo btmgmt pairable off
sudo btmgmt connectable off
🧯 If You Can't Patch
- Disable Bluetooth completely on affected systems
- Implement strict Bluetooth usage policies prohibiting connections to unknown devices
🔍 How to Verify
Check if Vulnerable:
Check BlueZ version: bluetoothctl --version or dpkg -l | grep bluezCheck Version:
bluetoothctl --version || dpkg -l | grep bluez || rpm -q bluezVerify Fix Applied:
Verify BlueZ version is updated and check for security patches in distribution changelog📡 Detection & Monitoring
Log Indicators:
- Unusual Bluetooth connection attempts in system logs
- AVRCP protocol errors in Bluetooth logs
Network Indicators:
- Unusual Bluetooth MAC addresses attempting connections
- Malformed AVRCP packets in Bluetooth traffic
SIEM Query:
source="bluetooth" AND (event="connection_failed" OR event="avrcp_error")