# CVE-2021-20874: Missing authorization in GroupSession Free edition, GroupSession byCloud, GroupSession ZION

> Remote unauthenticated attackers can access arbitrary files and obtain sensitive information due to incorrect permission assignments in GroupSession.

- **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 Dec 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-4xfx-j5qc-9qj6

## What is CVE-2021-20874?

CVE-2021-20874 is a high-severity missing authorization vulnerability in Japan Total System Co.,Ltd. GroupSession Free edition, GroupSession byCloud, GroupSession ZION, published on 24 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Incorrect permission assignment for critical resource vulnerability in GroupSession Free edition ver5.1.1 and earlier, GroupSession byCloud ver5.1.1 and earlier, and GroupSession ZION ver5.1.1 and earlier allows a remote unauthenticated attacker to access arbitrary files on the server and obtain sensitive information via unspecified vectors.

Weakness: CWE-732 (Incorrect Permission Assignment for Critical Resource)

## Which versions are affected by CVE-2021-20874?

It affects 1 product.


Products: Groupsession Groupsession.

## How do I fix CVE-2021-20874?

No fix has been published for CVE-2021-20874 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-20874 being exploited?

There is no known exploitation of CVE-2021-20874 in the wild and no public exploit code.

## Other vulnerabilities in Japan Total System Co.,Ltd. GroupSession Free edition, GroupSession byCloud, GroupSession ZION

- [CVE-2025-61987](https://insights.sbomify.com/CVE-2025-61987/): Cross-site request forgery in GroupSession Free edition (medium 6.9)
- [CVE-2021-20876](https://insights.sbomify.com/CVE-2021-20876/): Path traversal in GroupSession Free edition, GroupSession byCloud, GroupSession ZION (medium 6.8)
- [CVE-2017-2165](https://insights.sbomify.com/CVE-2017-2165/): Information disclosure in GroupSession (medium 6.5)
- [CVE-2021-20875](https://insights.sbomify.com/CVE-2021-20875/): Open redirect in GroupSession Free edition, GroupSession byCloud, GroupSession ZION (medium 6.1)
- [CVE-2021-20789](https://insights.sbomify.com/CVE-2021-20789/): Open redirect in GroupSession (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-20874 and fix it if it is affected.

What it is: CVE-2021-20874 is a high-severity missing authorization vulnerability in Japan Total System Co.,Ltd. GroupSession Free edition, GroupSession byCloud, GroupSession ZION, published on 24 Dec 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-2021-20874 in the wild and no public exploit code.

Affected product: Japan Total System Co.,Ltd. GroupSession Free edition, GroupSession byCloud, GroupSession ZION. 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-2021-20874/ (Markdown: https://insights.sbomify.com/CVE-2021-20874/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-20874
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-20874
- OSV: https://osv.dev/vulnerability/CVE-2021-20874

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-20874/
Summaries are generated and may contain mistakes; the official description above is the record.