# CVE-2023-3336: TN-5900 Series User Enumeration Vulnerability

> Remote attackers can enumerate valid users via the web login page, facilitating brute force attacks against the Moxa TN-5900 series.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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:** 5 Jul 2023
- **Updated:** 20 Nov 2024
- **Also known as:** GHSA-78g4-c5r9-6gh7

## What is CVE-2023-3336?

CVE-2023-3336 is a medium-severity vulnerability in Moxa TN-5900 Series, published on 5 Jul 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

TN-5900 Series version 3.3 and prior versions is vulnearble to user enumeration vulnerability. The vulnerability may allow a remote attacker to determine whether a user is valid during password recovery through the web login page and enable a brute force attack with valid users.

Weakness: CWE-203 (Observable Discrepancy), CWE-204 (Observable Response Discrepancy)

## Which versions are affected by CVE-2023-3336?

It affects 1 product.


Products: Moxa Tn-5900 Firmware.

## How do I fix CVE-2023-3336?

No fix has been published for CVE-2023-3336 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-3336 being exploited?

There is no known exploitation of CVE-2023-3336 in the wild and no public exploit code.

## Other vulnerabilities in Moxa TN-5900 Series

- [CVE-2021-46560](https://insights.sbomify.com/CVE-2021-46560/): Command injection in n/a (critical 9.8)
- [CVE-2023-33237](https://insights.sbomify.com/CVE-2023-33237/): Authentication Bypass Without Administrator Privilege (high 8.8)
- [CVE-2023-34213](https://insights.sbomify.com/CVE-2023-34213/): Second Order Command-injection Vulnerability in the Key-generation Function (high 8.8)
- [CVE-2021-46559](https://insights.sbomify.com/CVE-2021-46559/): Weak cryptography in n/a (high 7.5)
- [CVE-2023-34215](https://insights.sbomify.com/CVE-2023-34215/): Second Order Command-injection Vulnerability in the Certificate-generation Function (high 7.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-3336 and fix it if it is affected.

What it is: CVE-2023-3336 is a medium-severity vulnerability in Moxa TN-5900 Series, published on 5 Jul 2023. 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-2023-3336 in the wild and no public exploit code.

Affected product: Moxa TN-5900 Series. 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-2023-3336/ (Markdown: https://insights.sbomify.com/CVE-2023-3336/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-3336
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-3336
- OSV: https://osv.dev/vulnerability/CVE-2023-3336

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-3336/
Summaries are generated and may contain mistakes; the official description above is the record.