CVE-2021-27166Public exploitNetwork attack vector

Administrative CLI access via hardcoded enable password

Published Feb 10, 2021 · Updated Aug 3, 2024

Hard-coded credentials in the FiberHome HG6245D through RP2613 allow remote authenticated users to gain administrative CLI access. The proprietary Telnet CLI accepts the fixed string gpon as the enable-command password, changing a User prompt to the privileged Config prompt. Prior access to the Telnet CLI is required; successful elevation exposes configuration commands, while this flaw alone does not grant a root shell.

CVSS severity9.8
Critical
EPSS probability19.84%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Hard-coded credentials in the FiberHome HG6245D through RP2613 allow remote authenticated users to gain administrative CLI access. The proprietary Telnet CLI accepts the fixed string gpon as the enable-command password, changing a User prompt to the privileged Config prompt. Prior access to the Telnet CLI is required; successful elevation exposes configuration commands, while this flaw alone does not grant a root shell.

The record

CVE
CVE-2021-27166
Published
Feb 10, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-798, T1078.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 10, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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 exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-798Use of Hard-coded Credentials
T1078.001Valid Accounts: Default Accounts

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo