In this article you will learn how to add custom SpamAssassin Rules to Zimbra. This way you can filter email that may have fooled your spam filtering or mitigate vulnerabilities such as CVE-2024-21413 where file:// hyperlinks cause problems in MS Outlook. SpamAssasin localrules In this example we are going to filter email that contains the […]
Archive | Security & Privacy
Patch Release: Improved Language Support, Modern UI, Distribution Lists & Other Security Enhancements
Patch Security Severity: Low Deployment Risk: Medium This release focuses on improving user experience, enhancing group communication and essential security for the following editions Zimbra Daffodil 10.0.7 (Release Notes) Zimbra 9.0.0 Kepler Patch-39 (Release Notes) Patch updated on 28 Feb include the following in their respective releases What’s New Improved Language Support (Zimbra Daffodil) OnlyOffice […]
How to implement (external LDAP) authentication in a Zimbra Java Extension
Frequent readers of the Zimbra blog will know that Zimbra can be extended/customized by using Zimlets. By creating your own Zimlets you can add functionality to the UI (front-end) and the Java back-end, allowing you to cater to specific customer needs. Zimlets can be enabled globally or per user (group) Details on this can be […]
SMTP Smuggling in Zimbra Postfix a technical deepdive
E-mail providers like Microsoft Exchange Online and GMX allowed to pass <LF>.<CR><LF> sequence unfiltered from their outbound (sending mails) SMTP server to the inbound (receiving mails) SMTP server (postfix in our case). In the case of Postfix serving as an outbound/inbound (sending mails/receiving mails) server, it does not ignore the sequence ‘<LF>.<CR><LF>’; rather, it interprets […]
Zimbra and SMTP Smuggling attack on Postfix
Recently an SMTP Smuggling attack on Postfix was published, as mentioned by the Postfix project: Days before a 10+ day holiday break and associated production change freeze, SEC Consult has published an email spoofing attack that involves a composition of email services with specific differences in the way they handle line endings other than <CR><LF>. […]
Patch Release For Deprecated Files Deletion, OpenJDK Security Enhancement, Migration Support to Zimbra Daffodil (v10)
Patch Severity: High. This release addresses critical bug fixes and essential security updates Patch Release for the following editions Zimbra Daffodil 10.0.6 (Release Notes) Zimbra 9.0.0 Kepler Patch-38 (Release Notes) Zimbra 8.8.15 Joule Patch-45 (Release Notes) Patch updated on 18 Dec include the following in their respective releases What’s New OpenJDK has been upgraded to […]