# CVE-2021-34418: Pre-auth Null pointer crash in on-premise web console

> An unauthenticated attacker can crash the login service of Zoom On-Premise Connectors by sending a NULL byte during authentication.

- **Severity:** Medium 4.0 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Nov 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-9m9w-fffc-45mm

## What is CVE-2021-34418?

CVE-2021-34418 is a medium-severity vulnerability in Zoom On-Premise Meeting Connector, published on 11 Nov 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The login routine of the web console in the Zoom On-Premise Meeting Connector before version 4.6.239.20200613, Zoom On-Premise Meeting Connector MMR before version 4.6.239.20200613, Zoom On-Premise Recording Connector before version 3.8.42.20200905, Zoom On-Premise Virtual Room Connector before version 4.4.6344.20200612, and Zoom On-Premise Virtual Room Connector Load Balancer before version 2.5.5492.20200616 fails to validate that a NULL byte was sent while authenticating. This could lead to a crash of the login service.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2021-34418?

It affects 5 products.


Products: Zoom Zoom On-Premise Meeting Connector Controller, Zoom Zoom On-Premise Meeting Connector Mmr, Zoom Zoom On-Premise Recording Connector, Zoom Zoom On-Premise Virtual Room Connector, Zoom Zoom On-Premise Virtual Room Connector Load Balancer.

## How do I fix CVE-2021-34418?

No fix has been published for CVE-2021-34418 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-34418 being exploited?

There is no known exploitation of CVE-2021-34418 in the wild and no public exploit code.

## Other vulnerabilities in Zoom On-Premise Meeting Connector

- [CVE-2021-34417](https://insights.sbomify.com/CVE-2021-34417/): Authenticated remote command execution with root privileges via web console in MMR (high 7.9)
- [CVE-2022-22783](https://insights.sbomify.com/CVE-2022-22783/): Process memory exposure in Zoom on-premise Meeting services (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-34418 and fix it if it is affected.

What it is: CVE-2021-34418 is a medium-severity vulnerability in Zoom On-Premise Meeting Connector, published on 11 Nov 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-34418 in the wild and no public exploit code.

Affected product: Zoom On-Premise Meeting Connector. 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-2021-34418/ (Markdown: https://insights.sbomify.com/CVE-2021-34418/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-34418
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-34418
- OSV: https://osv.dev/vulnerability/CVE-2021-34418

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-34418/
Summaries are generated and may contain mistakes; the official description above is the record.