CVE-2022-20817: Cisco Ata 187 Analog Telephone Adapter Firmware

High severity, CVSS 7.4. EPSS: 1.2% chance of exploitation in the next 30 days.

A vulnerability in Cisco Unified IP Phones could allow an unauthenticated, remote attacker to impersonate another user's phone if the Cisco Unified Communications Manager (CUCM) is in secure mode. This vulnerability is due to improper key generation during the manufacturing process that could result in duplicated manufactured keys installed on multiple devices. An attacker could exploit this vulnerability by performing a machine-in-the-middle attack on the secure communication between the phone and the CUCM. A successful exploit could allow the attacker to impersonate another user's phone. This vulnerability cannot be addressed with software updates. There is a workaround that addresses this vulnerability.

Affected products

Cisco Ata 187 Analog Telephone Adapter Firmware: any version
Cisco Unified IP Phone 6911 Firmware: affected versions not specified
Cisco Unified IP Phone 6921 Firmware: affected versions not specified
Cisco Unified IP Phone 6941 Firmware: affected versions not specified
Cisco Unified IP Phone 6945 Firmware: affected versions not specified
Cisco Unified IP Phone 6961 Firmware: affected versions not specified
Cisco Unified IP Phone 8941 Firmware: affected versions not specified
Cisco Unified IP Phone 8945 Firmware: affected versions not specified
Cisco Unified IP Phone 8961 Firmware: affected versions not specified
Cisco Unified IP Phone 9951 Firmware: affected versions not specified
Cisco Unified IP Phone 9971 Firmware: affected versions not specified

Published 2022-06-15. Last modified 2026-06-17.