SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-27691

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…

CRITICAL 9.8EPSS 25.4%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 25.4%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.

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.

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
25.37% probability · 98th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-78, CWE-119
Affected
tendacn/g0 firmware · tendacn/g1 firmware · tendacn/g3 firmware
Source
cve@mitre.org
EPSS trend
0%15%30%26 October 2026: 25.37%26 October 202626 October 2026

EPSS 25.4% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.