# CVE-2021-25681: Information disclosure in n/a

> Attackers can exfiltrate data via DNS tunneling using exposed web servers in end-of-life AdTran phone manager appliances.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Apr 2021
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-rmmm-93q6-jw8j

## What is CVE-2021-25681?

CVE-2021-25681 is a high-severity vulnerability in n/a, published on 20 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

AdTran Personal Phone Manager 10.8.1 software is vulnerable to an issue that allows for exfiltration of data over DNS. This could allow for exposed AdTran Personal Phone Manager web servers to be used as DNS redirectors to tunnel arbitrary data over DNS. NOTE: The affected appliances NetVanta 7060 and NetVanta 7100 are considered End of Life and as such this issue will not be patched.

## Which versions are affected by CVE-2021-25681?

It affects 1 product.


Products: Adtran Personal Phone Manager.

## How do I fix CVE-2021-25681?

No fix has been published for CVE-2021-25681 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-25681 being exploited?

There is no known exploitation of CVE-2021-25681 in the wild and no public exploit code.

Public exploit code:

- Adtran Personal Phone Manager 10.8.1 - DNS Exfiltration (exploitdb)

## Other vulnerabilities in n/a

- [CVE-2021-25680](https://insights.sbomify.com/CVE-2021-25680/): Cross-site scripting in n/a (medium 6.1)
- [CVE-2021-25679](https://insights.sbomify.com/CVE-2021-25679/): Cross-site scripting in n/a (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-25681 and fix it if it is affected.

What it is: CVE-2021-25681 is a high-severity vulnerability in n/a, published on 20 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-25681 in the wild and no public exploit code.

Affected product: n/a. 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-2021-25681/ (Markdown: https://insights.sbomify.com/CVE-2021-25681/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-25681
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-25681
- OSV: https://osv.dev/vulnerability/CVE-2021-25681

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-25681/
Summaries are generated and may contain mistakes; the official description above is the record.