CVE-2020-27639: Mitel 6873i SIP Firmware

High severity, CVSS 8.1. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Mitel 6873i SIP Firmware: before 5.1.0 (fixed in 5.1.0); version 5.1.0 only
• Mitel 6930 SIP Firmware: before 5.1.0 (fixed in 5.1.0); version 5.1.0 only
• Mitel 6940 SIP Firmware: before 5.1.0 (fixed in 5.1.0); version 5.1.0 only

Published 2020-12-18. Last modified 2026-06-17.