The Common Vulnerabilities and Exposures (CVE) system has identified a security issue that requires attention. The CVE-2022-36868 vulnerability is associated with the MouseNKeyHidDevice application, which is susceptible to improper restriction of broadcasting Intent, leading to leakages of the connected Bluetooth device's MAC address. This long-read post examines the vulnerability details, potential exploits, and security measures to address the issue.

Vulnerability Description

The CVE-2022-36868 vulnerability is found in the MouseNKeyHidDevice application, specifically in versions prior to the SMR Oct-2022 Release 1 update. The application does not properly restrict the broadcasting of Intents when sending the connected Bluetooth device's MAC address. This allows other installed applications on the device to access the MAC address through the Intent, potentially compromising the user's private information and facilitating potential cyber-attacks.

Exploit Details

An attacker could exploit this vulnerability by creating a malicious application that listens for the broadcasted Intent. Upon receiving the Intent, the rogue application could read the connected Bluetooth device's MAC address and transmit it to a remote server controlled by the attacker, exposing the user to potential security risks.

Here is an example of a code snippet that demonstrates the vulnerability

// The code that sends the broadcast Intent
Intent intent = new Intent("com.example.APP.ACTION_MAC_ADDRESS");
intent.putExtra("mac_address", device.getAddress());
sendBroadcast(intent);

// The potentially malicious code in another app listening for the broadcast Intent
public class MaliciousReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if ("com.example.APP.ACTION_MAC_ADDRESS".equals(intent.getAction())) {
            String macAddress = intent.getStringExtra("mac_address");
            // Send the MAC address to the attacker's remote server
            sendDataToAttacker(macAddress);
        }
    }
}

Mitigation Recommendations

Users are recommended to update their MouseNKeyHidDevice applications to the latest version, specifically with the SMR Oct-2022 Release 1 update or higher. This would ensure proper restricting of broadcasting Intent and prevent the leakage of connected Bluetooth device's MAC address. Updates can be found on the official MouseNKeyHidDevice website or through in-app updates, which arrive periodically.

Developers are also advised to follow best practices for secure coding and restrict access to sensitive information by verifying the recipient's identity in the broadcast Intent. One way to accomplish this is by using explicit Intent targeting specific components rather than relying on implicit Intent broadcasting.

// Secure alternative: Using explicit Intent
Intent intent = new Intent("com.example.APP.ACTION_MAC_ADDRESS");
intent.setComponent(new ComponentName("com.example.targetapp", "com.example.targetapp.TargetReceiver"));
intent.putExtra("mac_address", device.getAddress());
sendBroadcast(intent);

Conclusion

The improper restriction of broadcasting Intent in MouseNKeyHidDevice prior to SMR Oct-2022 Release 1 has the potential to leak connected Bluetooth devices' MAC addresses. Users are strongly recommended to update to the latest version, and developers should follow secure coding practices to mitigate the risks associated with the vulnerability.

For more information on the CVE-2022-36868 vulnerability, please refer to the following sources

1. Original CVE Entry
2. National Vulnerability Database (NVD)

Stay vigilant, protect your privacy, and keep your applications up-to-date to minimize the threat of cyber-attacks!

Timeline

Published on: 10/07/2022 15:15:00 UTC
Last modified on: 10/11/2022 19:03:00 UTC