# 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.

- Page: https://www.vulneraibility.com/cve/CVE-2024-27443
- CVSS: 6.1
- Known exploited: yes, in CISA KEV since 2025-05-19; CISA due date 2025-06-09
- EPSS: 24.61%
- Detection templates only, no public exploit found: 1 Nuclei template
- CISA SSVC: exploitation active, automatable no, technical impact total (assessed 2025-05-21)
- Weakness: CWE-79
- Published: 2024-08-12

## Affected

- zimbra:collaboration

## References

- [other] https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.7#Security_Fixes
- [other] https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P39#Security_Fixes
- [advisory] https://www.welivesecurity.com/en/eset-research/operation-roundpress/
- [other] https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-27443

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Summary, impact and action are written by the vulneraibility.com AI analysis pipeline from the CVE record, NVD, CISA and FIRST data; verify against the references.