# CVE-2024-36257: Lack of permission check when updating the profile picture of a remote user (shared channels enabled)

> A malicious remote server can modify profile pictures of users belonging to other connected remote servers when shared channels are enabled.

- **Severity:** Low 2.7 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Jul 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-5cg2-wmx6-ccqv

## What is CVE-2024-36257?

CVE-2024-36257 is a low-severity missing authorization vulnerability in Mattermost Mattermost, published on 3 Jul 2024. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Mattermost versions 9.5.x <= 9.5.5 and 9.8.0, when using shared channels with multiple remote servers connected, fail to check that the remote server A requesting the server B to update the profile picture of a user is the remote that actually has the user as a local one . This allows a malicious remote A to change the profile images of users that belong to another remote server C that is connected to the server A.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2024-36257?

It affects 1 product.


Products: Mattermost Mattermost.

## How do I fix CVE-2024-36257?

No fix has been published for CVE-2024-36257 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-36257 being exploited?

There is no known exploitation of CVE-2024-36257 in the wild and no public exploit code.

## Other vulnerabilities in Mattermost Mattermost

- [CVE-2019-20851](https://insights.sbomify.com/CVE-2019-20851/): Path traversal in n/a (critical 9.1)
- [CVE-2024-39274](https://insights.sbomify.com/CVE-2024-39274/): Malicious remote can add users to arbitrary teams and channels (high 8.7)
- [CVE-2024-39777](https://insights.sbomify.com/CVE-2024-39777/): Malicious remote can invite itself to an arbitrary local channel (high 8.7)
- [CVE-2024-39830](https://insights.sbomify.com/CVE-2024-39830/): Timing attack during remote cluster token comparison when shared channels are enabled (high 8.1)
- [CVE-2023-3615](https://insights.sbomify.com/CVE-2023-3615/): Lack of server certificate validation in websockets connection (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-36257 and fix it if it is affected.

What it is: CVE-2024-36257 is a low-severity missing authorization vulnerability in Mattermost Mattermost, published on 3 Jul 2024. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-36257 in the wild and no public exploit code.

Affected product: Mattermost Mattermost. 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-2024-36257/ (Markdown: https://insights.sbomify.com/CVE-2024-36257/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-36257
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-36257
- OSV: https://osv.dev/vulnerability/CVE-2024-36257

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-36257/
Summaries are generated and may contain mistakes; the official description above is the record.