# CVE-2024-38518: bbb-web API additional parameters considered

> Attackers with valid join links can escalate privileges to moderator by injecting parameters into signed join URLs, requiring an upgrade to patched versions.

- **Severity:** Medium 4.6 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 28 Jun 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-4m48-49h7-f3c4

## What is CVE-2024-38518?

CVE-2024-38518 is a medium-severity vulnerability in bigbluebutton, published on 28 Jun 2024. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

BigBlueButton is an open-source virtual classroom designed to help teachers teach and learners learn. An attacker with a valid join link to a meeting can trick BigBlueButton into generating a signed join link with additional parameters. One of those parameters may be "role=moderator", allowing an attacker to join a meeting as moderator using a join link that was originally created for viewer access. This vulnerability has been patched in version(s) 2.6.18, 2.7.8 and 3.0.0-alpha.7.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2024-38518?


## How do I fix CVE-2024-38518?

No fix has been published for CVE-2024-38518 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-38518 being exploited?

There is no known exploitation of CVE-2024-38518 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-38518 and fix it if it is affected.

What it is: CVE-2024-38518 is a medium-severity vulnerability in bigbluebutton, published on 28 Jun 2024. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2024-38518 in the wild and no public exploit code.

Affected product: bigbluebutton. 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-2024-38518/ (Markdown: https://insights.sbomify.com/CVE-2024-38518/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-38518
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-38518
- OSV: https://osv.dev/vulnerability/CVE-2024-38518

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-38518/
Summaries are generated and may contain mistakes; the official description above is the record.