How can organizations defend against CVE-2019-6980?

The primary defense is to apply the official Zimbra patch released for CVE-2019-6980 and update the software to a non‑vulnerable version. Additionally, administrators should ensure that the memcached service is not exposed externally, restrict access to the IMAP port, and disable or mitigate the SSRF vulnerability (CVE-2019-9621) by limiting outbound proxy requests. For a broader perspective on securing exposed services, see the Sophos UTM Exploitation Analysis - Exporting Configuration Files for lessons on configuration hardening.