# CVE-2024-23184: Denial of service in OX Dovecot Pro

> An attacker can cause denial of service by sending emails with excessive address headers, consuming CPU resources on Dovecot servers.

- **Severity:** Medium 5.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/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:** Yes
- **Published:** 10 Sep 2024
- **Updated:** 4 Nov 2025
- **Also known as:** ALPINE-CVE-2024-23184, AZL-48981, AZL-49024, CLSA-2025-1753374470, DEBIAN-CVE-2024-23184, GHSA-5f48-j349-fj3m, UBUNTU-CVE-2024-23184

## What is CVE-2024-23184?

CVE-2024-23184 is a medium-severity denial of service vulnerability in Open-Xchange GmbH OX Dovecot Pro, published on 10 Sep 2024. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Having a large number of address headers (From, To, Cc, Bcc, etc.) becomes excessively CPU intensive. With 100k header lines CPU usage is already 12 seconds, and in a production environment we observed 500k header lines taking 18 minutes to parse. Since this can be triggered by external actors sending emails to a victim, this is a security issue. An external attacker can send specially crafted messages that consume target system resources and cause outage. One can implement restrictions on address headers on MTA component preceding Dovecot. No publicly available exploits are known.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2024-23184?


## How do I fix CVE-2024-23184?

Change a configuration setting.

## Is CVE-2024-23184 being exploited?

There is no known exploitation of CVE-2024-23184 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-23184 and fix it if it is affected.

What it is: CVE-2024-23184 is a medium-severity denial of service vulnerability in Open-Xchange GmbH OX Dovecot Pro, published on 10 Sep 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-2024-23184 in the wild and no public exploit code.

Affected product: Open-Xchange GmbH OX Dovecot Pro. 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-2024-23184/ (Markdown: https://insights.sbomify.com/CVE-2024-23184/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-23184
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-23184
- OSV: https://osv.dev/vulnerability/CVE-2024-23184

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-23184/
Summaries are generated and may contain mistakes; the official description above is the record.