{"id":"CVE-2023-34192","published":"2023-07-06T16:15:10Z","modified":"2026-06-17T06:03:05Z","title":"Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability","vendor":"Synacor","product":"Zimbra Collaboration Suite (ZCS)","tier":"core","eol":null,"description":{"text":"Cross Site Scripting vulnerability in Zimbra ZCS v.8.8.15 allows a remote authenticated attacker to execute arbitrary code via a crafted script to the /h/autoSaveDraft function.","provenance":"source","from":"NVD"},"summary":{"text":"A cross-site scripting flaw in the /h/autoSaveDraft function of Synacor's Zimbra Collaboration Suite (ZCS) allows script injection into its web interface. An attacker who is a remote, authenticated user can exploit it by supplying a crafted script and getting a victim to interact with the affected page.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-30T13:36:34Z"},"cvss":{"score":9.0,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.77266,"percentile":0.99554,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2025-02-25","dueDate":"2025-03-18","ransomware":false,"requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","notes":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories ; https://nvd.nist.gov/vuln/detail/CVE-2023-34192","provenance":"source"},"vulncheckKev":{"dateAdded":"2025-02-25","exploitedFirstSeen":"2025-02-25","ransomware":false,"evidence":[{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2025-02-25"},{"url":"https://cyble.com/resources/research-reports/global-cybersecurity-report/","date":"2025-12-11"},{"url":"https://www.loginsoft.com/reports/annually/vulnerability-intelligence-report-2025","date":"2026-01-20"}],"evidenceTotal":3,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"references":[{"url":"https://wiki.zimbra.com/wiki/Security_Center","tags":["Release Notes","Vendor Advisory"]},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy","tags":["Not Applicable"]},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories","tags":["Vendor Advisory"]},{"url":"https://wiki.zimbra.com/wiki/Security_Center","tags":["Release Notes","Vendor Advisory"]},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy","tags":["Not Applicable"]},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-34192","tags":["US Government Resource"]}],"techniques":[{"id":"T1055","name":"Process Injection","tactics":["privilege-escalation","stealth"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Cross-site Scripting (XSS)","mappingType":"exploitation_technique","evidence":[],"comment":"The /h/autoSaveDraft function in Zimbra Collaboration Suite can be targeted by an authenticated attacker's malicious scripts, facilitating arbitrary code execution, as well as session cookie theft.","confidence":"high"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Cross-site Scripting (XSS)","mappingType":"primary_impact","evidence":[],"comment":"The /h/autoSaveDraft function in Zimbra Collaboration Suite can be targeted by an authenticated attacker's malicious scripts, facilitating arbitrary code execution, as well as session cookie theft.","confidence":"high"},{"id":"T1185","name":"Browser Session Hijacking","tactics":["collection"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Cross-site Scripting (XSS)","mappingType":"secondary_impact","evidence":[],"comment":"The /h/autoSaveDraft function in Zimbra Collaboration Suite can be targeted by an authenticated attacker's malicious scripts, facilitating arbitrary code execution, as well as session cookie theft.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2023-38291","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2023-38291","exploited":true,"exploitedSince":"2025-02-25","provenance":"source"},"exploits":[],"exploitSources":{"nuclei":[{"id":"CVE-2023-34192","name":"Zimbra Collaboration Suite (ZCS) v.8.8.15 - Cross-Site Scripting","severity":"critical","path":"http/cves/2023/CVE-2023-34192.yaml","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2023/CVE-2023-34192.yaml"}],"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1055"],"provenance":"source"},{"stage":"primary","techniques":["T1059"],"provenance":"source"},{"stage":"secondary","techniques":["T1185"],"provenance":"source"}],"timeline":[{"date":"2023-07-06","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-34192","provenance":"source"},{"date":"2025-02-25","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","provenance":"source"},{"date":"2025-02-25","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2025-02-25","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2023-38291","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":600},"priority":{"score":69.2,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 612 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.91,"detail":"percentile 0.9955"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 nuclei template"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":6.3,"detail":"base score 9.0"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]},"lineage":{"familyId":"fam-class-synacor-zimbra-collaboration-suite-zcs-cwe-79"}}