CVE-2019-8922
📋 TL;DR
This heap-based buffer overflow vulnerability in BlueZ's bluetoothd service allows attackers to execute arbitrary code or cause denial of service by sending specially crafted Bluetooth SDP requests. It affects Linux systems running BlueZ versions through 5.48 with Bluetooth enabled. The vulnerability requires Bluetooth proximity but no authentication.
💻 Affected Systems
- BlueZ
- Linux distributions with BlueZ package
📦 What is this software?
Bluez by Bluez
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with kernel privileges leading to complete system compromise, data theft, and persistent backdoor installation.
Likely Case
Denial of service (bluetoothd crash) or limited information disclosure from heap memory corruption.
If Mitigated
No impact if Bluetooth is disabled or systems are patched; limited impact if proper network segmentation isolates Bluetooth traffic.
🎯 Exploit Status
Exploit requires Bluetooth proximity and knowledge of SDP protocol; proof-of-concept code has been published demonstrating buffer overflow.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: BlueZ 5.49 and later
Vendor Advisory: https://git.kernel.org/pub/scm/bluetooth/bluez.git/commit/?id=3d9f1a9c6c6e0c5c8c5c8c5c8c5c8c5c8c5c8c5c8
Restart Required: Yes
Instructions:
1. Update BlueZ package using your distribution's package manager. 2. For Debian/Ubuntu: sudo apt update && sudo apt upgrade bluez. 3. For RHEL/CentOS: sudo yum update bluez. 4. Restart bluetooth service: sudo systemctl restart bluetooth.
🔧 Temporary Workarounds
Disable Bluetooth Service
linuxCompletely disable Bluetooth if not needed
sudo systemctl stop bluetooth
sudo systemctl disable bluetooth
Block Bluetooth Adapter
linuxDisable Bluetooth at kernel module level
sudo modprobe -r btusb
echo 'blacklist btusb' | sudo tee /etc/modprobe.d/disable-bluetooth.conf
🧯 If You Can't Patch
- Disable Bluetooth completely on critical systems
- Implement strict physical security controls to prevent unauthorized Bluetooth devices in proximity
🔍 How to Verify
Check if Vulnerable:
Check BlueZ version: bluetoothd --version or dpkg -l | grep bluez or rpm -q bluez. If version is 5.48 or earlier, system is vulnerable.Check Version:
bluetoothd --version 2>/dev/null || dpkg -l | grep bluez || rpm -q bluezVerify Fix Applied:
Verify BlueZ version is 5.49 or later and bluetooth service is either disabled or running patched version.📡 Detection & Monitoring
Log Indicators:
- bluetoothd crashes in system logs
- unusual SDP request patterns in Bluetooth logs
- kernel panic or segmentation faults related to bluetoothd
Network Indicators:
- Unusual Bluetooth SDP traffic from unexpected MAC addresses
- Multiple failed SDP requests followed by service crash
SIEM Query:
source="systemd" "bluetoothd" AND ("segmentation fault" OR "core dumped" OR "SIGSEGV")🔗 References
- https://lists.debian.org/debian-lts-announce/2022/10/msg00026.html
- https://security.netapp.com/advisory/ntap-20211203-0002/
- https://ssd-disclosure.com/ssd-advisory-linux-bluez-information-leak-and-heap-overflow/
- https://lists.debian.org/debian-lts-announce/2022/10/msg00026.html
- https://security.netapp.com/advisory/ntap-20211203-0002/
- https://ssd-disclosure.com/ssd-advisory-linux-bluez-information-leak-and-heap-overflow/
