First published: Thu Aug 15 2024(Updated: )
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.
Credit: security@open-xchange.com security@open-xchange.com
Affected Software | Affected Version | How to fix |
---|---|---|
debian/dovecot | <=1:2.3.13+dfsg1-2+deb11u1 | 1:2.3.13+dfsg1-2+deb11u2 1:2.3.19.1+dfsg1-2.1+deb12u1 1:2.3.21.1+dfsg1-1 |
Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.