CVE-2020-36963
Published: 28 January 2026
Summary
CVE-2020-36963 is a high-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Intelbras Router RF (inferred from references). Its CVSS base score is 7.5 (High).
Operationally, ranked in the top 45.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requires established identification and authentication to unlock, mitigating missing authentication for continued system access.
Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.
Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.
Guarantees critical functions are protected by mandatory invocation of the access control mechanism.
Auditing sessions makes it possible to detect access to critical functions without required authentication.
The assessment process confirms authentication is present and effective for critical functions, preventing exploitation from missing authentication.
Certification assesses that critical functions have required authentication controls in place.
Disabling non-essential functions and services eliminates the need to secure them, reducing exposure from missing authentication on unnecessary components.
NVD Description
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.
Deeper analysisAI
CVE-2020-36963 is an authentication bypass vulnerability in the Intelbras Router RF 301K firmware version 1.1.2. The flaw enables unauthenticated attackers to download sensitive router configuration files by sending a specific HTTP GET request to the /cgi-bin/DownloadCfg/RouterCfm.cfg endpoint, bypassing any required authentication mechanisms. It is classified under CWE-306 (Missing Authentication for Critical Function) and carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).
Remote unauthenticated attackers can exploit this vulnerability over the network with low complexity and no user interaction. Exploitation allows retrieval of confidential router configuration data, potentially exposing credentials, network settings, or other sensitive information stored in the RouterCfm.cfg file.
Advisories and references for this CVE include a proof-of-concept exploit published on Exploit-DB (https://www.exploit-db.com/exploits/49126), the vendor's website at Intelbras (https://www.intelbras.com/pt-br/), and a Vulncheck advisory (https://www.vulncheck.com/advisories/intelbras-router-rf-k-authentication-bypass). These resources provide further details on the issue, though specific patch or mitigation guidance is not detailed in the available CVE information.
Details
- CWE(s)