# CVE-2021-21734: Information disclosure in ZTE PON MDU devices

> Authenticated users can retrieve sensitive plaintext information from ZTE PON MDU devices via command input.

- **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:** 28 May 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-h8vq-x2w7-p2c6

## What is CVE-2021-21734?

CVE-2021-21734 is a medium-severity vulnerability in ZTE PON MDU devices, published on 28 May 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Some PON MDU devices of ZTE stored sensitive information in plaintext, and users with login authority can obtain it by inputing command. This affects: ZTE PON MDU device ZXA10 F821 V1.7.0P3T22, ZXA10 F822 V1.4.3T6, ZXA10 F819 V1.2.1T5, ZXA10 F832 V1.1.1T7, ZXA10 F839 V1.1.0T8, ZXA10 F809 V3.2.1T1, ZXA10 F822P V1.1.1T7, ZXA10 F832 V2.00.00.01

Weakness: CWE-312 (Cleartext Storage of Sensitive Information)

## Which versions are affected by CVE-2021-21734?

It affects 8 products.


Products: Zte Zxa10 F809 Firmware, Zte Zxa10 F819 Firmware, Zte Zxa10 F821 Firmware, Zte Zxa10 F822 Firmware, Zte Zxa10 F822p Firmware, Zte Zxa10 F832 Firmware, Zte Zxa10 F832v2 Firmware, Zte Zxa10 F839 Firmware.

## How do I fix CVE-2021-21734?

No fix has been published for CVE-2021-21734 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-21734 being exploited?

There is no known exploitation of CVE-2021-21734 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21734 and fix it if it is affected.

What it is: CVE-2021-21734 is a medium-severity vulnerability in ZTE PON MDU devices, published on 28 May 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-2021-21734 in the wild and no public exploit code.

Affected product: ZTE PON MDU devices. 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-2021-21734/ (Markdown: https://insights.sbomify.com/CVE-2021-21734/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21734
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21734
- OSV: https://osv.dev/vulnerability/CVE-2021-21734

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21734/
Summaries are generated and may contain mistakes; the official description above is the record.