# CVE-2021-40639: Information disclosure in n/a

> Attackers can access sensitive configuration files in Jfinal CMS due to improper access control, leading to information disclosure.

- **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:** 15 Sep 2021
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-8m3p-xv8v-vgp2

## What is CVE-2021-40639?

CVE-2021-40639 is a high-severity vulnerability in Jflyfox Jfinal Cms, published on 15 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper access control in Jfinal CMS 5.1.0 allows attackers to access sensitive information via /classes/conf/db.properties&config=filemanager.config.js.

Weakness: CWE-863 (Incorrect Authorization), CWE-668 (Exposure of Resource to Wrong Sphere)

## Which versions are affected by CVE-2021-40639?

It affects 1 product.


Products: Jflyfox Jfinal Cms.

## How do I fix CVE-2021-40639?

No fix has been published for CVE-2021-40639 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-40639 being exploited?

There is no known exploitation of CVE-2021-40639 in the wild and no public exploit code.

## Other vulnerabilities in Jflyfox Jfinal Cms

- [CVE-2024-53477](https://insights.sbomify.com/CVE-2024-53477/): Deserialization in n/a (critical 9.8)
- [CVE-2023-47503](https://insights.sbomify.com/CVE-2023-47503/): Code injection in n/a (critical 9.8)
- [CVE-2023-30349](https://insights.sbomify.com/CVE-2023-30349/): Remote code execution in JFinal CMS (critical 9.8)
- [CVE-2022-37204](https://insights.sbomify.com/CVE-2022-37204/): SQL injection in n/a (critical 9.8)
- [CVE-2022-37203](https://insights.sbomify.com/CVE-2022-37203/): SQL injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-40639 and fix it if it is affected.

What it is: CVE-2021-40639 is a high-severity vulnerability in Jflyfox Jfinal Cms, published on 15 Sep 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-2021-40639 in the wild and no public exploit code.

Affected product: Jflyfox Jfinal Cms. 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-2021-40639/ (Markdown: https://insights.sbomify.com/CVE-2021-40639/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40639
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-40639
- OSV: https://osv.dev/vulnerability/CVE-2021-40639

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-40639/
Summaries are generated and may contain mistakes; the official description above is the record.