CVE-2021-21735Public exploit

Credential disclosure via unauthenticated wizard endpoints

Published Jun 10, 2021 · Updated May 26, 2026

Information disclosure in ZTE ZXHN H168N Firmware 3.5.0_EG1T4_TE and earlier allows remote attackers to read setup credentials. The QuickSetupEnable routing branch allowlists wizard handlers whose unauthenticated GetPassword action returns PPPoE usernames and the WLAN key passphrase. The request requires adjacent-network reachability but no web login; administrative compromise is limited to deployments that reuse the Wi-Fi key as the default administrator password.

CVSS severity6.5
Medium
EPSS probability0.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in ZTE ZXHN H168N Firmware 3.5.0_EG1T4_TE and earlier allows remote attackers to read setup credentials. The QuickSetupEnable routing branch allowlists wizard handlers whose unauthenticated GetPassword action returns PPPoE usernames and the WLAN key passphrase. The request requires adjacent-network reachability but no web login; administrative compromise is limited to deployments that reuse the Wi-Fi key as the default administrator password.

The record

CVE
CVE-2021-21735
Published
Jun 10, 2021
Updated
May 26, 2026
Vendor
ZTE Corporation
Product
ZXHN H168N Firmware
Classifications
CWE-281
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 10, 2021CVE publishedPublication date reported by the CVE source.
  2. May 26, 2026Record 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=All versions up to V3.5.0_EG1T4_TE

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

ZTE Corporation · ZXHN H168N Firmwareversion=All versions up to V3.5.0_EG1T4_TE

Published CVSS scores

6.5NVDCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
3.5ZTE CorporationCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-281Improper Preservation of Permissions

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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