# CVE-2021-27561: Yealink Device Management Server-Side Request Forgery (SSRF) Vulnerability

Source: https://junglewise.ai/threats/cve-2021-27561-yealink-device-management-server-side-request-forgery-ssrf  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-11-03. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2021-27561 · Severity: critical · CVSS 9.8 · Exploited in the wild · Published 2021-11-03

Yealink Device Management (DM) version 3.6.0.20 is vulnerable to an unauthenticated command injection vulnerability via the /sm/api/v1/firewall/zone/services URI. An attacker can exploit this to execute commands as root, potentially leading to full system compromise.

Vendors: [Yealink](https://junglewise.ai/threats/vendors/yealink).

## Quick answers

**Is CVE-2021-27561 exploited in the wild?** Yes. CVE-2021-27561 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.

**How severe is CVE-2021-27561?** Critical severity, with a CVSS score of 9.8, published 3 November 2021.

**Which products and versions are affected?** Yealink Device Management (DM) 3.6.0.20.

**Is there a fix for CVE-2021-27561?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2021-27561 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2021-27561?** Check whether you run Yealink Device Management. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Yealink Device Management (DM) 3.6.0.20

## Timeline

- 2021-10-15: disclosed: NVD Published Date
- 2021-11-03: kev added: Date added to CISA Known Exploited Vulnerabilities Catalog