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.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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
Which versions are affected by CVE-2024-23184?
How do I fix CVE-2024-23184?
Change a configuration setting.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-23184 being exploited?
There is no known exploitation of CVE-2024-23184 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2024-23184, AZL-48981, AZL-49024, CLSA-2025-1753374470, DEBIAN-CVE-2024-23184, GHSA-5f48-j349-fj3m and 1 more.