{"id":"CVE-2024-27443","aliases":["EUVD-2024-24646","GHSA-qrvg-mg33-q843"],"status":"published","title":"An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. A Cross-Site Scripting (XSS)...","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.","severity":{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.24606,"percentile":0.9791,"model":"v2026.06.15"},"facts":{"in_kev":true,"known_exploited":true,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2024-08-12T00:00:00Z","modified":"2026-10-28T02:31:12Z","kev":{"date_added":"2025-05-19","due_date":"2025-06-09","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.","known_ransomware_use":"Unknown"},"exploitation":[{"source":"euvd","since":"2025-05-19"},{"source":"kev","since":"2025-05-19"}],"exploits":[{"source":"nuclei","id":"CVE-2024-27443","title":"Zimbra Collaboration - Cross-Site Scripting (XSS)","type":"detection template","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2024/CVE-2024-27443.yaml"}],"products":[{"vendor":"synacor","product":"zimbra collaboration suite (zcs)"},{"vendor":"zimbra","product":"collaboration"}],"references":[{"url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.7#Security_Fixes","tags":["Release Notes","web"]},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P39#Security_Fixes","tags":["Release Notes","web"]},{"url":"https://www.welivesecurity.com/en/eset-research/operation-roundpress/","tags":["third-party-advisory","Press/Media Coverage","advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-27443","tags":["government-resource","US Government Resource","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-27443","tags":["advisory"]},{"url":"https://www.welivesecurity.com/en/eset-research/operation-roundpress"},{"url":"https://github.com/advisories/GHSA-qrvg-mg33-q843"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/27xxx/CVE-2024-27443.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2024-27443","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.","status":"published","published":"2024-08-12T00:00:00Z","modified":"2025-10-21T22:55:48.688Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"adp"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:34:12.982241Z"}],"euvd":[{"id":"EUVD-2024-24646","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.","status":"published","published":"2024-08-12T00:00:00Z","modified":"2025-10-21T22:55:48Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"exploited_since":"2025-05-19","updated_at":"2026-11-02T20:31:28.525814Z"}],"ghsa":[{"id":"GHSA-qrvg-mg33-q843","title":"An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. A Cross-Site Scripting (XSS)...","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.","status":"published","published":"2024-08-12T15:30:53Z","modified":"2025-10-22T00:34:11Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:04:08.734574Z"}],"kev":[{"id":"CVE-2024-27443","title":"Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability","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.","cwes":["CWE-79"],"kev":{"date_added":"2025-05-19","due_date":"2025-06-09","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.","known_ransomware_use":"Unknown"},"updated_at":"2026-11-02T17:00:15.999436Z"}],"nvd":[{"id":"CVE-2024-27443","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.","status":"published","published":"2024-08-12T15:15:20.283Z","modified":"2026-06-17T07:19:54.627Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:10:18.563492Z"}],"osv":[{"id":"CVE-2024-27443","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.","status":"published","published":"2024-08-12T00:00:00Z","modified":"2026-10-28T02:31:12.880896496Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:39.569658Z"}]}}