MEDIUM CISA KEV

CVE-2024-27443

CVSS v3

6.1

MEDIUM

EPSS Score

30.1%

exploit probability

CISA KEV

Yes

known exploited

Exploitation

SSVC status

Description

An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. A Cross-Site Scripting (XSS) vulnerability exists in the CalendarInvite feature of the Zimbra webmail classic user interface, because of improper input validation in the handling of the calendar header. An attacker can exploit this via an email message containing a crafted calendar header with an embedded XSS payload. When a victim views this message in the Zimbra webmail classic interface, the payload is executed in the context of the victim's session, potentially leading to execution of arbitrary JavaScript code.

CISA Known Exploited Vulnerability

Date Added
5/19/2025
Patch Due Date
6/9/2025
Ransomware Use
Unknown

Technical details

Published
8/12/2024

Frequently asked questions

What is CVE-2024-27443?

An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. A Cross-Site Scripting (XSS) vulnerability exists in the CalendarInvite feature of the Zimbra webmail classic user interface, because of improper input validation in the handling of the calendar header. An attacker can exploit this via an email message containing a crafted calendar header with an embedded XSS payload. When a victim views this message in the Zimbra webmail classic interface, the payload is executed in the context of the victim's session, potentially leading to execution of arbitrary JavaScript code.

Is CVE-2024-27443 actively exploited?

Yes. CVE-2024-27443 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 6/9/2025.

What is the CVSS score for CVE-2024-27443?

CVE-2024-27443 has a CVSS v3 base score of 6.1 (MEDIUM severity).

Is CVE-2024-27443 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.