Critical XSS Vulnerability CVE-2024-27443 Affects 129,000 Zimbra Servers, Linked to Sednit Group

A critical Cross-Site Scripting (XSS) vulnerability, identified as CVE-2024-27443, has been detected within the CalendarInvite feature of the Zimbra Collaboration Suite. This vulnerability poses a significant risk, as it is currently being actively exploited by malicious actors.

The flaw allows attackers to execute arbitrary scripts in the context of the user’s browser. This can result in unauthorized actions, data exfiltration, or account compromise. The primary vector for exploitation appears to be through crafted calendar invitation messages that, when opened by an unsuspecting user, can execute malicious code.

Organizations utilizing the Zimbra Collaboration Suite are urged to implement appropriate security measures immediately. This includes applying relevant patches, updating to the most recent version of the software, and conducting thorough assessments of any calendar invitations received during this period.

Users should be cautious of unsolicited invitations, especially those that originate from unknown sources. Additionally, it is advisable to educate employees about the potential risks associated with XSS vulnerabilities and the importance of vigilance when interacting with email and calendar applications.

To mitigate the risk associated with CVE-2024-27443, Zimbra has released a security advisory, detailing the patching process and best practices for preventing exploitation. Administrators are encouraged to follow these guidelines closely to safeguard their systems against potential attacks.

In summary, the CVE-2024-27443 vulnerability in the Zimbra Collaboration Suite presents a critical security risk. Immediate action is necessary to protect sensitive information and maintain the integrity of collaboration tools within the organization.