CVEs / CVE-2021-27561
CVE-2021-27561: Yealink Device Management Server-Side Request Forgery (SSRF) Vulnerability
- Known exploited in the CISA KEV catalog since 3 Nov 2021
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 82.8% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Yealink Device Management contains a server-side request forgery (SSRF) vulnerability that allows for unauthenticated remote code execution.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| n/a n/a | n/a | — |
Exploitation
| In CISA KEV since | 3 Nov 2021 |
|---|---|
| Due date for US federal agencies | 17 Nov 2021 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-78 |
References
- CVE-2021-27561 on NVD
- CVE-2021-27561 in the CISA KEV catalog
- https://ssd-disclosure.com/?p=4688 Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27561 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.