# CVE-2016-8643: Missing authorization in Moodle 2.x and 3.x

> Non-admin site managers can improperly edit administrator accounts via web services, leading to privilege escalation and unauthorized data modification.

- **Severity:** Medium 4.3 (`CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/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:** 20 Jan 2017
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-69xm-pcg8-8qxm, UBUNTU-CVE-2016-8643

## What is CVE-2016-8643?

CVE-2016-8643 is a medium-severity missing authorization vulnerability in Moodle Moodle, published on 20 Jan 2017. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

In Moodle 2.x and 3.x, non-admin site managers may accidentally edit admins via web services.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2016-8643?

It affects 1 product.


Products: Moodle Moodle.

## How do I fix CVE-2016-8643?

No fix has been published for CVE-2016-8643 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-8643 being exploited?

There is no known exploitation of CVE-2016-8643 in the wild and no public exploit code.

## Other vulnerabilities in Moodle Moodle

- [CVE-2006-4935](https://insights.sbomify.com/CVE-2006-4935/): File upload in n/a (critical 10.0)
- [CVE-2006-4936](https://insights.sbomify.com/CVE-2006-4936/): Moodle does not properly validate module instance id (critical 10.0)
- [CVE-2004-2233](https://insights.sbomify.com/CVE-2004-2233/): Unknown "front page vulnerability with Moodle servers" for Moodle before 1.3.2 has unknown impact and attack vectors. (critical 10.0)
- [CVE-2004-2235](https://insights.sbomify.com/CVE-2004-2235/): Cross-site scripting in n/a (critical 10.0)
- [CVE-2004-2236](https://insights.sbomify.com/CVE-2004-2236/): Other in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-8643 and fix it if it is affected.

What it is: CVE-2016-8643 is a medium-severity missing authorization vulnerability in Moodle Moodle, published on 20 Jan 2017. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2016-8643 in the wild and no public exploit code.

Affected product: Moodle Moodle. 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-2016-8643/ (Markdown: https://insights.sbomify.com/CVE-2016-8643/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-8643
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-8643
- OSV: https://osv.dev/vulnerability/CVE-2016-8643

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-8643/
Summaries are generated and may contain mistakes; the official description above is the record.