CVE-2021-21735
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA ZTE product has an information leak vulnerability. Due to improper permission settings, an attacker with ordinary user permissions could exploit this vulnerability to obtain some sensitive user information through the wizard page without authentication. This affects ZXHN H168N all versions up to V3.5.0_EG1T4_TE.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThe ZTE ZXHN H168N router has an information disclosure vulnerability where improper permission settings on the web interface's wizard page allow an authenticated (or potentially unauthenticated) attacker with ordinary user privileges to access sensitive user information without proper authorization.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 3.5.0_eg1t4_teCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify device modelAccess the router's web administration interface and check the device info page, or look for the model label on the router hardware itselfAffected if Device is not a ZTE ZXHN H168N router - different models are not affected by this CVE
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Check firmware versionLog into the router web interface and navigate to the status or system information page to view the installed firmware versionAffected if Firmware version is 3.5.0_eg1t4_te or any version lower than it - versions above 3.5.0_eg1t4_te are not affected
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Verify web interface accessibilityAttempt to access the router's web interface over HTTP/HTTPS from a browserAffected if The web management interface is exposed and reachable on the network
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Test wizard page access with ordinary userLog in to the router with a standard user account (not admin) and navigate to the wizard page URL or examine if the wizard functionality is accessible without elevated privilegesAffected if An authenticated user with ordinary (non-administrator) privileges can access the wizard page and view sensitive user information that should be restricted to administrators
A user is affected if they have a ZTE ZXHN H168N router running firmware version 3.5.0_eg1t4_te or earlier with its web interface accessible and the wizard page permits ordinary user access to sensitive data
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply any available firmware update from ZTE. If no update exists, consider network segmentation to limit access to the router's administrative interface and disable remote management if not required.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
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Free · runs locallyCheck whether your project pulls in CVE-2021-21735 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-21735 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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