Is CVE-2024-27443 actively exploited?

Yes. CVE-2024-27443 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2024-27443 be exploited remotely?

The attack vector of CVE-2024-27443 has not been classified yet.

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

CVE-2024-27443 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2024-27443

HIGHCISA KEVIN THE WILD

CVE-2024-27443

Published: May 19, 2025

EPSS:30.11%probability of exploitation in 30 daysPercentile:96.6th

Official Description

Zimbra Collaboration contains a cross-site scripting (XSS) vulnerability in the CalendarInvite feature of the Zimbra webmail classic user interface. An attacker can exploit this vulnerability via an email message containing a crafted calendar header, leading to the execution of arbitrary JavaScript code.

NVD Source

CISA KEV Advisory

Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability

Added to KEV: 2025-05-19Federal patch deadline: 2025-06-09

Required Action (CISA)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Risk Analysis

This cross-site scripting (XSS) vulnerability in Zimbra Collaboration's CalendarInvite feature allows an attacker to execute arbitrary JavaScript code. The high severity, confirmed in-the-wild exploitation, and an EPSS score of 0.30112 make this a critical vulnerability that is actively being leveraged by attackers.

This vulnerability is actively exploited in the wild and is included in CISA's KEV catalog. The attack can be initiated remotely via a crafted email.

Recommended Action

Update Zimbra Collaboration to a patched version to remediate the XSS vulnerability in the CalendarInvite feature. Users should exercise caution with calendar invitations from untrusted sources.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2024-27443 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2024-27443 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.