Actively exploited · Published Oct 15, 2021 · Assigned by mitre

CVE-2021-27561

Critical 9.8 Exploited

In plain English

A critical-severity OS command injection in Device Management from Yealink. Attackers are actively exploiting it in the wild (listed by CISA on November 3, 2021). The chance it is exploited in the next 30 days is estimated at 82.9% (higher than 99.7% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei. Apply updates per vendor instructions.

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)82.9%top 0.3% of all CVEs

Exploited in the wildYesCISA KEV since Nov 3, 2021

Attack tooling1Nuclei

CISA guidance

Apply updates per vendor instructions.

Federal agencies must remediate by Nov 17, 2021.

Official 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 products (as reported)

Vendor	Product	Versions
n/a	n/a	n/a

Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://ssd-disclosure.com/?p=4688 x_refsource_MISC
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27561 government-resource