# CVE-2021-40651: Path traversal in n/a

> Attackers can read arbitrary files from the server filesystem via a local file inclusion vulnerability in the modname parameter.

- **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:** 29 Sep 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-7g4r-gjr5-j9m7

## What is CVE-2021-40651?

CVE-2021-40651 is a medium-severity path traversal vulnerability in Os4ed Opensis, published on 29 Sep 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

OS4Ed OpenSIS Community 8.0 is vulnerable to a local file inclusion vulnerability in Modules.php (modname parameter), which can disclose arbitrary file from the server's filesystem as long as the application has access to the file.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2021-40651?

It affects 1 product.


Products: Os4ed Opensis.

## How do I fix CVE-2021-40651?

No fix has been published for CVE-2021-40651 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-40651 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-40651 exists.

Public exploit code:

- OpenSIS 8.0 'modname' - Directory Traversal (exploitdb)
- OS4Ed OpenSIS Community 8.0 - Local File Inclusion (nuclei): http/cves/2021/CVE-2021-40651.yaml

## Other vulnerabilities in Os4ed Opensis

- [CVE-2020-6143](https://insights.sbomify.com/CVE-2020-6143/): Code injection in OS4Ed (critical 10.0)
- [CVE-2020-6144](https://insights.sbomify.com/CVE-2020-6144/): Code injection in OS4Ed (critical 10.0)
- [CVE-2020-6142](https://insights.sbomify.com/CVE-2020-6142/): Path traversal in OS4Ed (critical 9.9)
- [CVE-2021-41691](https://insights.sbomify.com/CVE-2021-41691/): SQL injection in n/a (critical 9.8)
- [CVE-2025-22926](https://insights.sbomify.com/CVE-2025-22926/): Path traversal in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-40651 and fix it if it is affected.

What it is: CVE-2021-40651 is a medium-severity path traversal vulnerability in Os4ed Opensis, published on 29 Sep 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-40651 exists.

Affected product: Os4ed Opensis. 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-2021-40651/ (Markdown: https://insights.sbomify.com/CVE-2021-40651/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40651
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-40651
- OSV: https://osv.dev/vulnerability/CVE-2021-40651

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-40651/
Summaries are generated and may contain mistakes; the official description above is the record.