{"id":"CVE-2024-27443","url":"https://www.cyber-defence.io/tools/cve/CVE-2024-27443","generatedAt":"2026-10-31T09:13:55.833Z","title":"Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability","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.","published":"2024-08-12T15:15:20.000Z","lastModified":"2026-06-17T07:19:55.000Z","status":"Analyzed","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"cwe":["CWE-79"],"affected":["zimbra/collaboration"],"epss":{"score":0.24606,"percentile":0.97881,"date":"2026-10-30","history":[]},"kev":{"listed":true,"dateAdded":"2025-05-19","dueDate":"2025-06-09","knownRansomwareCampaignUse":"Unknown","notes":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.\nhttps://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P46#Security_Fixes ; https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P39#Security_Fixes ; https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.7#Security_Fixes ; https://nvd.nist.gov/vuln/detail/CVE-2024-27443"},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"Known to be exploited in the wild (CISA KEV, CISA remediation deadline 9 June 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise."},"changes":[],"references":[{"url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.7#Security_Fixes","tags":["Release Notes"],"source":"cve@mitre.org"},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P39#Security_Fixes","tags":["Release Notes"],"source":"cve@mitre.org"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-27443","tags":["US Government Resource"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://www.welivesecurity.com/en/eset-research/operation-roundpress/","tags":["Press/Media Coverage"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2024-27443","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}