# CVE-2021-41638: Auth bypass in n/a

> Remote attackers can access local files on MELAG FTP Server by using only a valid username, bypassing complete authentication checks.

- **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:** 24 Jun 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-m56w-5xpw-w7wc

## What is CVE-2021-41638?

CVE-2021-41638 is a high-severity authentication bypass vulnerability in n/a, published on 24 Jun 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The authentication checks of the MELAG FTP Server in version 2.2.0.4 are incomplete, which allows a remote attacker to access local files only by using a valid username.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2021-41638?

It affects 1 product.


Products: Melag Ftp Server.

## How do I fix CVE-2021-41638?

No fix has been published for CVE-2021-41638 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-41638 being exploited?

There is no known exploitation of CVE-2021-41638 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-41635](https://insights.sbomify.com/CVE-2021-41635/): Privilege escalation in n/a (high 8.8)
- [CVE-2021-41637](https://insights.sbomify.com/CVE-2021-41637/): Information disclosure in n/a (high 7.1)
- [CVE-2021-41636](https://insights.sbomify.com/CVE-2021-41636/): Path traversal in n/a (medium 6.5)
- [CVE-2021-41639](https://insights.sbomify.com/CVE-2021-41639/): Information disclosure in n/a (medium 5.5)
- [CVE-2021-41634](https://insights.sbomify.com/CVE-2021-41634/): Information disclosure in n/a (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-41638 and fix it if it is affected.

What it is: CVE-2021-41638 is a high-severity authentication bypass vulnerability in n/a, published on 24 Jun 2022. 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-2021-41638 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-2021-41638/ (Markdown: https://insights.sbomify.com/CVE-2021-41638/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-41638
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-41638
- OSV: https://osv.dev/vulnerability/CVE-2021-41638

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-41638/
Summaries are generated and may contain mistakes; the official description above is the record.