# CVE-2024-21630: Zulip non-admins can invite new users to streams they would not otherwise be able to add existing users to

> Non-admin users can invite new members to streams despite admin-only restrictions, requiring specific permission configurations to exploit.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/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:** 25 Jan 2024
- **Updated:** 29 May 2025

## What is CVE-2024-21630?

CVE-2024-21630 is a medium-severity missing authorization vulnerability in zulip, published on 25 Jan 2024. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Zulip is an open-source team collaboration tool. A vulnerability in version 8.0 is similar to CVE-2023-32677, but applies to multi-use invitations, not single-use invitation links as in the prior CVE. Specifically, it applies when the installation has configured non-admins to be able to invite users and create multi-use invitations, and has also configured only admins to be able to invite users to streams. As in CVE-2023-32677, this does not let users invite new users to arbitrary streams, only to streams that the inviter can already see. Version 8.1 fixes this issue. As a workaround, administrators can limit sending of invitations down to users who also have the permission to add users to streams.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2024-21630?

It affects 1 product.


Products: Zulip Zulip Server.

## How do I fix CVE-2024-21630?

No fix has been published for CVE-2024-21630 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-21630 being exploited?

There is no known exploitation of CVE-2024-21630 in the wild and no public exploit code.

## Other vulnerabilities in zulip

- [CVE-2019-18933](https://insights.sbomify.com/CVE-2019-18933/): Information disclosure in n/a (critical 9.8)
- [CVE-2020-15070](https://insights.sbomify.com/CVE-2020-15070/): Code injection in n/a (high 8.8)
- [CVE-2017-0910](https://insights.sbomify.com/CVE-2017-0910/): Missing authorization in Zulip Server (high 8.8)
- [CVE-2025-31478](https://insights.sbomify.com/CVE-2025-31478/): Zulip Authentication Backend Configuration Bypass (high 8.2)
- [CVE-2023-33186](https://insights.sbomify.com/CVE-2023-33186/): Cross-site scripting vulnerability in Zulip Server development branch via topic tooltip (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-21630 and fix it if it is affected.

What it is: CVE-2024-21630 is a medium-severity missing authorization vulnerability in zulip, published on 25 Jan 2024. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-21630 in the wild and no public exploit code.

Affected product: zulip. 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-2024-21630/ (Markdown: https://insights.sbomify.com/CVE-2024-21630/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-21630
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-21630
- OSV: https://osv.dev/vulnerability/CVE-2024-21630

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-21630/
Summaries are generated and may contain mistakes; the official description above is the record.