XSS in Zimbra Collaboration
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 h…
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.195 (97.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Zimbra Collaboration — versions 9.0.0
- N/a — versions n/a
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Public proof-of-concept exploits
References
- cve@mitre.org (Release Notes)
- cve@mitre.org (Release Notes)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Press/Media Coverage)
Frequently asked questions
- What is CVE-2024-27443?
- CVE-2024-27443 is a medium-severity vulnerability in Zimbra Collaboration, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2024-08-12.
- How severe is CVE-2024-27443?
- Medium severity. CVSS v3 base score is 6.1 out of 10.
- Is CVE-2024-27443 known to be exploited?
- Yes. CVE-2024-27443 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-05-19), indicating it is being actively exploited. 5 public proof-of-concept repositories are indexed.