CVE-2019-9670 — Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity Reference
Overview
Synacor Zimbra Collaboration Suite (ZCS) contains an improper restriction of XML external entity (XXE) vulnerability in the mailboxd component.
Vulnerability details
- CVE ID
- CVE-2019-9670
- Vulnerability
- Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity Reference
- Vendor
- Synacor
- Affected products
- Synacor: Zimbra Collaboration Suite (ZCS)
- Severity
- HIGH
- Exploitation status
- Actively exploited in the wild (CISA KEV)
- Published
- 2022-01-10
Remediation guidance
CVE-2019-9670 is in CISA's Known Exploited Vulnerabilities (KEV) catalog — U.S. federal civilian agencies are required to remediate it under Binding Operational Directive 22-01. Treat it as a priority for every environment.
Apply the vendor's official security update for Synacor the affected product as soon as possible. Where a patch is unavailable, apply vendor mitigations or isolate/segment exposed systems.
Hunt for indicators of compromise tied to this vulnerability and confirm logging/EDR coverage on affected assets.
Authoritative references
Remediate CVE-2019-9670 — and stay ahead of the next one
CVE-2019-9670 is listed in the CISA KEV catalog as actively exploited — treat remediation as urgent. Scan your domain free to see whether CVE-2019-9670 and other Synacor issues affect you and get a prioritized remediation report (full report from ₹999) — or stream the full feed of 1,600+ actively-exploited CVEs straight into your SOC.
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