CVE intelligence and bounded remediation

CVE-2021-20161 — Trendnet AC2600 TEW-827DRU version 2.08B01 does not have sufficient protections for the UART functionality

High CVSS 7.2

Trendnet AC2600 TEW-827DRU version 2.08B01 does not have sufficient protections for the UART functionality. A malicious actor with physical access to the device is able to connect to the UART port via a serial connection. No username or password is required and the user is given a root shell with full control of the device.

Severity
High
CVSS
7.2 (2.0)
Published
2021-12-30
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-287, CWE-306

Affected products

  • trendnet / tew-827dru_firmware / 2.08b01

Matched remediation archetype

Authentication bypass and missing authentication

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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