# CVE-2024-31204: mailcow Cross-site Scripting Vulnerability via Exception Handler

> Attackers can inject malicious scripts into the mailcow admin panel via unsanitized exception details, leading to session hijacking and unauthorized administrative actions.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 4 Apr 2024
- **Updated:** 12 Dec 2024
- **Also known as:** GHSA-fp6h-63w4-5hcm

## What is CVE-2024-31204?

CVE-2024-31204 is a medium-severity cross-site scripting vulnerability in mailcow-dockerized, published on 4 Apr 2024. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

mailcow: dockerized is an open source groupware/email suite based on docker. A security vulnerability has been identified in mailcow affecting versions prior to 2024-04. This vulnerability resides in the exception handling mechanism, specifically when not operating in DEV_MODE. The system saves exception details into a session array without proper sanitization or encoding. These details are later rendered into HTML and executed in a JavaScript block within the user's browser, without adequate escaping of HTML entities. This flaw allows for Cross-Site Scripting (XSS) attacks, where attackers can inject malicious scripts into the admin panel by triggering exceptions with controlled input. The exploitation method involves using any function that might throw an exception with user-controllable argument. This issue can lead to session hijacking and unauthorized administrative actions, posing a significant security risk. Version 2024-04 contains a fix for the issue.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2024-31204?

It affects 1 product.


Products: Mailcow Mailcow\.

## How do I fix CVE-2024-31204?

No fix has been published for CVE-2024-31204 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-31204 being exploited?

There is no known exploitation of CVE-2024-31204 in the wild and no public exploit code.

## Other vulnerabilities in mailcow-dockerized

- [CVE-2025-53909](https://insights.sbomify.com/CVE-2025-53909/): mailcow: dockerized vulnerable to SSTI in Quota and Quarantine Notification Template (critical 9.1)
- [CVE-2024-24760](https://insights.sbomify.com/CVE-2024-24760/): Mailcow Docker Container Exposure to Local Network (high 8.8)
- [CVE-2023-34108](https://insights.sbomify.com/CVE-2023-34108/): Manipulation of Internal Dovecot Variables in mailcow via crafted Passwords (high 8.8)
- [CVE-2022-31138](https://insights.sbomify.com/CVE-2022-31138/): OS Command Injection in mailcow (high 8.8)
- [CVE-2022-31245](https://insights.sbomify.com/CVE-2022-31245/): Command injection in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-31204 and fix it if it is affected.

What it is: CVE-2024-31204 is a medium-severity cross-site scripting vulnerability in mailcow-dockerized, published on 4 Apr 2024. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2024-31204 in the wild and no public exploit code.

Affected product: mailcow-dockerized. 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-2024-31204/ (Markdown: https://insights.sbomify.com/CVE-2024-31204/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-31204
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-31204
- OSV: https://osv.dev/vulnerability/CVE-2024-31204

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From sbomify Insights: https://insights.sbomify.com/CVE-2024-31204/
Summaries are generated and may contain mistakes; the official description above is the record.