CVE-2018-16221: Yealink Ultra-Elegant IP Phone SIP-t41p Firmware

High severity, CVSS 8.0. EPSS: 1.5% chance of exploitation in the next 30 days.

The diagnostics web interface in the Yeahlink Ultra-elegant IP Phone SIP-T41P (firmware 66.83.0.35) does not validate (escape) the path information (path traversal), which allows an authenticated remote attacker to get access to privileged information (e.g., /etc/passwd) via path traversal (relative path information in the file parameter of the corresponding POST request).

Affected products

• Yealink Ultra-Elegant IP Phone SIP-t41p Firmware: version 66.83.0.35 only

Published 2019-05-29. Last modified 2026-06-17.