# CVE-2021-21735: Information disclosure in ZXHN H168N

> An attacker can access sensitive user information via the wizard page without authentication due to improper permission settings on ZTE routers.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Jun 2021
- **Updated:** 26 May 2026
- **Also known as:** GHSA-j3rv-rh4f-4rf6

## What is CVE-2021-21735?

CVE-2021-21735 is a medium-severity vulnerability in ZXHN H168N, published on 10 Jun 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A 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.

Weakness: CWE-281 (Improper Preservation of Permissions)

## Which versions are affected by CVE-2021-21735?

It affects 1 product.


Products: Zte Zxhn H168n Firmware.

## How do I fix CVE-2021-21735?

No fix has been published for CVE-2021-21735 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-21735 being exploited?

There is no known exploitation of CVE-2021-21735 in the wild and no public exploit code.

Public exploit code:

- CVE-2021-21735 write-up: ZTE ZXHN H168N V3.5 wizard-page information leak, firmware routing flaw, and the path from exposed PPPoE/WLAN data to full admin compromise. (github_poc): https://github.com/minanagehsalalma/cve-2021-21735-zte-zxhn-h168n-admin-compromise

## Other vulnerabilities in ZXHN H168N

- [CVE-2021-21730](https://insights.sbomify.com/CVE-2021-21730/): Auth bypass in ZXHN H168N (critical 9.8)
- [CVE-2018-7357](https://insights.sbomify.com/CVE-2018-7357/): Missing authorization in ZXHN H168N (medium 6.5)
- [CVE-2018-7358](https://insights.sbomify.com/CVE-2018-7358/): Auth bypass in ZXHN H168N (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21735 and fix it if it is affected.

What it is: CVE-2021-21735 is a medium-severity vulnerability in ZXHN H168N, published on 10 Jun 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-21735 in the wild and no public exploit code.

Affected product: ZXHN H168N. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-21735/ (Markdown: https://insights.sbomify.com/CVE-2021-21735/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21735
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21735
- OSV: https://osv.dev/vulnerability/CVE-2021-21735

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21735/
Summaries are generated and may contain mistakes; the official description above is the record.