CVE-2021-27561
Published 2021-10-15 · Updated 2026-06-17 · Source cve@mitre.org
Summary
CVE-2021-27561 is a critical-severity (CVSS 9.8) vulnerability in Yealink Device Management. CISA added it to the Known Exploited Vulnerabilities catalog on November 3, 2021, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by November 17, 2021. CISA does not currently list it as used in ransomware campaigns.
All 1 known-exploited Yealink vulnerabilities →Description
Yealink Device Management (DM) 3.6.0.20 allows command injection as root via the /sm/api/v1/firewall/zone/services URI, without authentication.
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA Known-Exploited Vulnerability
Product: Yealink — Device Management
Name: Yealink Device Management Server-Side Request Forgery (SSRF) Vulnerability
Date added: 2021-11-03 · Due: 2021-11-17
Required action: Apply updates per vendor instructions.