CVE-2021-20159Known exploitationNetwork attack vector

Root command execution via syslog parameter injection

Published Dec 30, 2021 · Updated Aug 3, 2024

Command injection in TRENDnet TEW-827DRU Firmware 2.08B01 allows remote authenticated users to execute root commands via the system-log configuration. The backend system() call passes the user-controlled cameo.cameo.syslog_server parameter without safe neutralization after a reboot, so a management-interface user can trigger command execution and compromise router confidentiality, integrity, and availability.

CVSS severity8.8
High
EPSS probability3.11%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in TRENDnet TEW-827DRU Firmware 2.08B01 allows remote authenticated users to execute root commands via the system-log configuration. The backend system() call passes the user-controlled cameo.cameo.syslog_server parameter without safe neutralization after a reboot, so a management-interface user can trigger command execution and compromise router confidentiality, integrity, and availability.

The record

CVE
CVE-2021-20159
Published
Dec 30, 2021
Updated
Aug 3, 2024
Vendor
TRENDnet
Product
TEW-827DRU Firmware
Classifications
CWE-78, T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.08B01

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

TRENDnet · TEW-827DRU Firmwareversion=2.08B01

Published CVSS scores

9.0NVDAV:N/AC:L/Au:S/C:C/I:C/A:C
9.8TenableCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.8NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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