CVE-2020-27639 : Exploit Details and Defense Strategies

Mitel MiVoice SIP Phones Bluetooth Pairing Vulnerability

Understanding CVE-2020-27639

What is CVE-2020-27639?

The Bluetooth handset of Mitel MiVoice 6873i, 6930, and 6940 SIP phones with firmware before 5.1.0.SP6 could allow an unauthenticated attacker within Bluetooth range to pair a rogue Bluetooth device when a phone handset loses connection, due to an improper pairing mechanism. A successful exploit could allow an attacker to eavesdrop on conversations.

The Impact of CVE-2020-27639

This vulnerability could lead to unauthorized access and potential eavesdropping on sensitive conversations, compromising confidentiality.

Technical Details of CVE-2020-27639

Vulnerability Description

The vulnerability arises from an improper Bluetooth pairing mechanism in Mitel MiVoice SIP phones, enabling unauthorized pairing with rogue devices.

Affected Systems and Versions

Mitel MiVoice 6873i, 6930, and 6940 SIP phones with firmware versions before 5.1.0.SP6

Exploitation Mechanism

An unauthenticated attacker within Bluetooth range can exploit the vulnerability to pair a rogue Bluetooth device when the phone handset loses connection.

Mitigation and Prevention

Immediate Steps to Take

Update affected devices to firmware version 5.1.0.SP6 or later to mitigate the vulnerability.
Disable Bluetooth when not in use to reduce the attack surface.

Long-Term Security Practices

Regularly monitor for security advisories and updates from Mitel.
Implement network segmentation to isolate critical devices from potential threats.

Patching and Updates

Apply security patches and firmware updates promptly to address known vulnerabilities.