CVE-2021-21730

CLI access via brute-force attempts

Published Apr 13, 2021 · Updated Aug 3, 2024

Improper access control in ZTE ZXHN H168N Firmware V3.5.0_TY.T6 allows local users to access the CLI through brute-force attempts. ZTE has not disclosed which CLI access-control check fails or how attempted credentials bypass it. Exploitation requires local access and exposes information available through the device command interface.

CVSS severity6.2
Medium
EPSS probability1.00%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in ZTE ZXHN H168N Firmware V3.5.0_TY.T6 allows local users to access the CLI through brute-force attempts. ZTE has not disclosed which CLI access-control check fails or how attempted credentials bypass it. Exploitation requires local access and exposes information available through the device command interface.

The record

CVE
CVE-2021-21730
Published
Apr 13, 2021
Updated
Aug 3, 2024
Vendor
ZTE Corporation
Product
ZXHN H168N Firmware
Classifications
T1110
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 13, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=V3.5.0_TY.T6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

ZTE Corporation · ZXHN H168N Firmwareversion=V3.5.0_TY.T6

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
6.2ZTE CorporationCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/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.

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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1110Brute Force

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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