CVE-2021-27165Public exploitNetwork attack vector

Privileged CLI access via hard-coded credentials

Published Feb 10, 2021 · Updated Aug 3, 2024

Hard-coded credentials in FiberHome HG6245D firmware through RP2613 allow remote attackers to access the Telnet management CLI. The port 23 daemon accepts the invariant gpon/gpon login and the same gpon value for enable mode, yielding a privileged Config prompt. The CLI is blocked by default on IPv4 but reachable over exposed IPv6, and separate management backdoors can enable it on IPv4.

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

What happened

Hard-coded credentials in FiberHome HG6245D firmware through RP2613 allow remote attackers to access the Telnet management CLI. The port 23 daemon accepts the invariant gpon/gpon login and the same gpon value for enable mode, yielding a privileged Config prompt. The CLI is blocked by default on IPv4 but reachable over exposed IPv6, and separate management backdoors can enable it on IPv4.

The record

CVE
CVE-2021-27165
Published
Feb 10, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-798, T1078.001
Attack vector
network
Privileges
unauthenticated

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

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.0National Vulnerability DatabaseAV:N/AC:L/Au:N/C:P/I:N/A:N

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.

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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
Privilegesunauthenticated
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

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Your stack

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