CVE intelligence and bounded remediation

CVE-2020-36963 — Intelbras Router RF 301K firmware security vulnerability

High CVSS 8.7

Intelbras Router RF 301K firmware version 1.1.2 contains an authentication bypass vulnerability that allows unauthenticated attackers to download router configuration files. Attackers can send a specific HTTP GET request to /cgi-bin/DownloadCfg/RouterCfm.cfg to retrieve sensitive router configuration without authentication.

Severity
High
CVSS
8.7 (4.0)
Published
2026-01-28
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-306

Affected products

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Matched remediation archetype

Authentication bypass and missing authentication

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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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