# CVE-2023-32678: Missing authorization in zulip

> Former subscribers to private streams can edit, move, or delete messages they previously accessed, violating access controls.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/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 Aug 2023
- **Updated:** 30 Sep 2024
- **Also known as:** GHSA-q3wg-jm9p-35fj

## What is CVE-2023-32678?

CVE-2023-32678 is a medium-severity missing authorization vulnerability in zulip, published on 25 Aug 2023. 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 with topic-based threading that combines email and chat. Users who used to be subscribed to a private stream and have been removed from it since retain the ability to edit messages/topics, move messages to other streams, and delete messages that they used to have access to, if other relevant organization permissions allow these actions. For example, a user may be able to edit or delete their old messages they posted in such a private stream. An administrator will be able to delete old messages (that they had access to) from the private stream. This issue was fixed in Zulip Server version 7.3.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2023-32678?

It affects 1 product.


Products: Zulip Zulip Server.

## How do I fix CVE-2023-32678?

No fix has been published for CVE-2023-32678 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-32678 being exploited?

There is no known exploitation of CVE-2023-32678 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-2023-32678 and fix it if it is affected.

What it is: CVE-2023-32678 is a medium-severity missing authorization vulnerability in zulip, published on 25 Aug 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-32678 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-2023-32678/ (Markdown: https://insights.sbomify.com/CVE-2023-32678/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-32678
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-32678
- OSV: https://osv.dev/vulnerability/CVE-2023-32678

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-32678/
Summaries are generated and may contain mistakes; the official description above is the record.