Is CVE-2021-27691 actively exploited?

No active exploitation of CVE-2021-27691 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-27691 be exploited remotely?

Yes. CVE-2021-27691 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-27691?

CVE-2021-27691 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2021-27691

CRITICAL

CVE-2021-27691

CWE-78Published: April 16, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

Command Injection in Tenda G0 routers with firmware versions v15.11.0.6(9039)_CN and v15.11.0.5(5876)_CN , and Tenda G1 and G3 routers with firmware versions v15.11.0.17(9502)_CN or v15.11.0.16(9024)_CN allows remote attackers to execute arbitrary OS commands via a crafted action/setDebugCfg request. This occurs because the "formSetDebugCfg" function executes glibc's system function with untrusted input.

NVD Source

Technical Analysis

CVE-2021-27691 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.