Vulnerability Intelligence Report
Yealink Device Management Server-Side Request Forgery (SSRF) Vulnerability
CVE-2021-27561
Yealink Device Management (DM) 3.6.0.20 allows command injection as root via the /sm/api/v1/firewall/zone/services URI, without authentication.
CISA KEV
Nuclei Template
SSVC: Active Exploitation
Automatable
CVSS Base Score
9.8
CRITICAL
Exploitability:3.9
Impact Score:5.9
EPSS Probability:82.52%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
—
Authentication
—
Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-78 ↗CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| yealink | device_management | all |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
CISA KEV
ACTIVE IN CATALOG
Nuclei Template
SCANNER AVAILABLE
EPSS Score
82.516%
GitHub Advisory
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | MITRE Corporation · N/A · USA |
| Reserved | 2021-02-22T00:00:00 |
| Published | 2021-10-15T17:11:45 |
| Last Updated | 2025-10-21T23:25:28 |
Community Chatter & Buzz