Security Digest · Vulnerability record · Known exploited
CVE-2023-34192: Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
Exploited in the wild (CISA KEV). 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.
CISA KEV · added 2025-02-25 CVSS 9.0 Critical EPSS 77.3% · p99.6
Should you act?
Exploited: patch now if you run it
CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Yes, if you run Synacor Zimbra Collaboration Suite (ZCS). CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-02-25, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-03-18; treat that as the outer limit, not the target.
- EPSS 77.3%, percentile 99.6: FIRST’s model estimates a 77.3% chance of exploitation activity in the next 30 days, higher than 99.6% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
What it is
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.
CISA’s summary
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting (XSS) vulnerability that allows a remote authenticated attacker to execute arbitrary code via a crafted script to the /h/autoSaveDraft function.
Weakness type: CWE-79.
Product: Synacor Zimbra Collaboration Suite (ZCS) · Assigned by: mitre · Published: 2023-07-06
Affected and fixed versions
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| n/a | n/a | see vendor advisory |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADP | 3.1 | 9 Critical | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: low (any account)
- User interaction: required (a user must click/open something)
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: added 2025-02-25; federal due date 2025-03-18. Known ransomware use: Unknown.
- CISA 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.
- CISA SSVC assessment: exploitation active, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 77.27% probability of exploitation activity in the next 30 days; percentile 99.6.
Timeline
- — CVE record published by mitre
- — Added to CISA’s Known Exploited Vulnerabilities catalog
- — CISA remediation deadline for US federal agencies
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- Listed in CISA KEV notes (wiki.zimbra.com) wiki.zimbra.com
Vulnerability records
- CVE.org record CVE-2023-34192 cve.org
- NVD entry CVE-2023-34192 nvd.nist.gov
Government
Other references from the CVE record and advisory
- wiki.zimbra.com wiki.zimbra.com
- wiki.zimbra.com wiki.zimbra.com
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