CVE intelligence and bounded remediation

CVE-2022-21173 — Elecom Wrh-300Bk3 Firmware security vulnerability

High CVSS 8.8

Hidden functionality vulnerability in ELECOM LAN routers (WRH-300BK3 firmware v1.05 and earlier, WRH-300WH3 firmware v1.05 and earlier, WRH-300BK3-S firmware v1.05 and earlier, WRH-300DR3-S firmware v1.05 and earlier, WRH-300LB3-S firmware v1.05 and earlier, WRH-300PN3-S firmware v1.05 and earlier, WRH-300WH3-S firmware v1.05 and earlier, and WRH-300YG3-S firmware v1.05 and earlier) allows an attacker on the adjacent network to execute an arbitrary OS command via unspecified vectors.

Severity
High
CVSS
8.8 (3.1)
Published
2022-02-08
CISA KEV
Not currently listed
Ecosystem
operating-system

Affected products

  • elecom / wrh-300bk3_firmware
  • elecom / wrh-300wh3_firmware
  • elecom / wrh-300bk3-s_firmware
  • elecom / wrh-300wh3-s_firmware
  • elecom / wrh-300lb3-s_firmware
  • elecom / wrh-300pn3-s_firmware

Showing 6 representative product identities from 8 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Command, code, expression, and template injection

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Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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