CVE-2024-45434

Executive Summary

CVE-2024-45434 is a critical Use-After-Free (UAF) vulnerability in the OpenSynergy BlueSDK (Blue SDK) Bluetooth stack, affecting versions through 6.x. The flaw allows an attacker to remotely execute arbitrary code in the context of the user account under which the Bluetooth process runs. No public proof-of-concept (PoC) or patch details are currently available, but the vulnerability is classified as high severity due to its potential for remote code execution (RCE) in Bluetooth-enabled systems.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It affects a proprietary Bluetooth SDK (BlueSDK) from OpenSynergy, commonly integrated into embedded systems, automotive infotainment, and IoT devices. Organizations using BlueSDK should treat this as a supply chain risk and verify the integrity of their Bluetooth stack components.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (No official CVSS vector provided; estimated high severity based on RCE potential)
• Attack Vector: Adjacent Network (Bluetooth range)
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High
• Threat Level: Critical (Remote Code Execution without authentication)

Deep Dive & Mechanics

The vulnerability resides in the BlueSDK Bluetooth stack, specifically in the handling of object lifetimes. A Use-After-Free occurs when the software continues to use a memory pointer after the associated memory has been freed. In this case, the Bluetooth stack fails to validate the existence of an object before performing operations on it, allowing an attacker to trigger a dangling pointer.

Attack Scenario:

1. An attacker within Bluetooth range sends a crafted Bluetooth packet to the target device.
2. The packet triggers a sequence of operations that frees a memory object while a reference to it remains.
3. The attacker then exploits the freed memory to overwrite critical data structures, leading to arbitrary code execution.
4. The code executes with the privileges of the Bluetooth process (typically a user account), enabling further compromise.

Root Cause: Lack of proper object validation before use in the BlueSDK Bluetooth stack. This is a classic CWE-416 vulnerability.

Vulnerable vs. Patched Code

Since no patch is available, the following is a hypothetical example of the vulnerable pattern and a potential fix.

Vulnerable Code (C-like pseudocode):

void process_bluetooth_packet(packet_t *pkt) {
    object_t *obj = find_object(pkt->id);
    // No check if obj is NULL or freed
    obj->process(pkt->data);  // Use-After-Free if obj was freed
    free(obj);                // Free after use (if not already freed)
}

Patched Code (Hypothetical):

void process_bluetooth_packet(packet_t *pkt) {
    object_t *obj = find_object(pkt->id);
    if (obj == NULL) {
        return;  // Validate object exists
    }
    // Use reference counting or lock to prevent premature free
    retain(obj);
    obj->process(pkt->data);
    release(obj);
}

Exploitation & Lab Setup

Red Team

Lab Setup:

• Target: Device running BlueSDK 6.x (e.g., embedded Linux system with Bluetooth)
• Attacker: Linux machine with Bluetooth adapter (e.g., BlueZ stack)
• Tools: Python with pwn library, custom Bluetooth packet crafting (e.g., using scapy)

Exploitation Steps:

1. Identify the target Bluetooth MAC address using hcitool scan.
2. Craft a malicious Bluetooth L2CAP packet that triggers the UAF condition.
3. Send the packet repeatedly to increase the chance of exploitation.
4. Use heap spraying techniques to control the freed memory.
5. Execute shellcode to gain a reverse shell.

Example Python script (conceptual):

from scapy.all import *
import bluetooth

target_mac = "00:11:22:33:44:55"
# Craft a malformed packet (specific to BlueSDK internals)
packet = L2CAP_Hdr(len=0x100) / Raw(b"\x41" * 0x100)
# Send via raw socket
sock = bluetooth.BluetoothSocket(bluetooth.L2CAP)
sock.connect((target_mac, 0x1001))
sock.send(bytes(packet))
sock.close()

Blue Team

Detection:

• Monitor Bluetooth traffic for malformed L2CAP packets with unusual lengths or patterns.
• Use host-based IDS to detect abnormal memory access patterns in the Bluetooth process.
• Enable Bluetooth logging and correlate with system crashes.

Hunting:

• Search for Bluetooth process crashes (e.g., bluetoothd or BlueSDK daemon).
• Analyze memory dumps for signs of heap corruption.
• Check for unexpected Bluetooth connections from unknown devices.

Indicators of Compromise (IOCs)

• Network: Unusual Bluetooth L2CAP packets with non-standard channel IDs or payload sizes.
• Host: Bluetooth process crashes (e.g., segmentation faults) in bluetoothd or BlueSDK logs.
• Memory: Heap corruption patterns in Bluetooth stack memory regions.
• File: Modified Bluetooth stack binaries or libraries (e.g., libbluetooth.so).
• Registry: (Windows) Unusual Bluetooth driver entries or service configurations.

Detection Engineering

YARA Rule

rule CVE_2024_45434_BlueSDK_UAF {
    meta:
        description = "Detects BlueSDK binaries potentially vulnerable to CVE-2024-45434"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-45434"
    strings:
        $s1 = "BlueSDK" ascii wide nocase
        $s2 = "find_object" ascii wide
        $s3 = "process_bluetooth_packet" ascii wide
    condition:
        all of them
}

Sigma Rule

title: CVE-2024-45434 BlueSDK Use-After-Free Exploitation
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects potential exploitation of CVE-2024-45434 via Bluetooth process crashes
author: Valters IT
logsource:
    product: linux
    service: syslog
detection:
    selection:
        - "bluetoothd" and "segfault"
        - "BlueSDK" and "crash"
    condition: selection
falsepositives:
    - Legitimate Bluetooth stack bugs
level: high

Suricata Rule

alert bluetooth any any -> any any (msg:"CVE-2024-45434 BlueSDK UAF Exploit Attempt"; content:"|41 41 41 41|"; offset:0; depth:100; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

• Patch: No official patch available. Contact OpenSynergy for updates.
• Workaround: Disable Bluetooth if not required. Use Bluetooth firewalls to restrict connections.
• Mitigation: Implement memory safety checks (e.g., AddressSanitizer) in development. Use privilege separation for Bluetooth processes.
• Monitoring: Deploy the above detection rules and monitor for anomalous Bluetooth activity.
• Vendor Response: Monitor OpenSynergy’s security advisories for future patches.

Valters IT
Securing Digital Frontiers