CVE-2021-27561

9.8 criticalKEVEPSS 83%

Critical (9.8) in Yealink Device Management. In CISA KEV since 2021-11-03. EPSS 83% chance of exploitation in the next 30 days.

Yealink Device Management (DM) 3.6.0.20 allows command injection as root via the /sm/api/v1/firewall/zone/services URI, without authentication.

Severity

9.8 critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 83% chance of exploitation in the next 30 days; higher than 99% of CVEs (scores of 2026-10-31)
CISA KEV: listed 2021-11-03, due 2021-11-17
CWE: CWE-78
Published: 2021-10-15
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19