# CVE-2019-9670: Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity Reference

Source: https://junglewise.ai/threats/cve-2019-9670-synacor-zimbra-collaboration-suite-zcs-improper-restriction-of-xml  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-01-10. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2019-9670 · Severity: critical · CVSS 9.8 · Exploited in the wild · Published 2022-01-10

The mailboxd component in Synacor Zimbra Collaboration Suite (ZCS) contains an XML External Entity (XXE) injection vulnerability. The flaw is specifically present in the Autodiscover/Autodiscover.xml handler, allowing remote attackers to access sensitive information or potentially achieve further compromise.

Technologies: [Synacor Zimbra Collaboration Suite (ZCS)](https://junglewise.ai/threats/technologies/zimbra-collaboration-suite-zcs). Vendors: [Synacor](https://junglewise.ai/threats/vendors/synacor).

## Quick answers

**Is CVE-2019-9670 exploited in the wild?** Yes. CVE-2019-9670 is known to be exploited in the wild, first recorded on 10 January 2022. Treat it as urgent.

**How severe is CVE-2019-9670?** Critical severity, with a CVSS score of 9.8, published 10 January 2022.

**Which products and versions are affected?** Synacor Zimbra Collaboration Suite 8.7.x before 8.7.11p10.

**Is there a fix for CVE-2019-9670?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2019-9670 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2019-9670?** Check whether you run Synacor Zimbra Collaboration Suite (ZCS). Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Synacor Zimbra Collaboration Suite 8.7.x before 8.7.11p10

## Timeline

- 2019-03-11: disclosed: Initial CVE assignment/publication date based on CVE ID year and external references.
- 2022-01-10: kev added: Added to CISA Known Exploited Vulnerabilities Catalog.
- 2022-01-10: advisory: NVD publication date.
- 2022-01-10: exploited: Confirmed as exploited in the wild by CISA.

## Related threats

- [Zimbra Collaboration Suite OS command injection in SMTP](https://junglewise.ai/threats/cve-2026-73570-zimbra-collaboration-suite-os-command-injection-in-smtp)
- [Synacor Zimbra Collaboration Suite XSS in Classic UI](https://junglewise.ai/threats/cve-2025-48700-synacor-zimbra-collaboration-suite-xss-in-classic-ui)
- [Synacor Zimbra Collaboration Suite stored XSS in Classic UI](https://junglewise.ai/threats/cve-2025-66376-synacor-zimbra-collaboration-suite-stored-xss-in-classic-ui)
- [Synacor Zimbra Collaboration Suite file inclusion in RestFilter servlet](https://junglewise.ai/threats/cve-2025-68645-synacor-zimbra-collaboration-suite-file-inclusion-in-restfilter)
- [Synacor Zimbra Collaboration Suite XSS in Classic Web Client](https://junglewise.ai/threats/cve-2025-27915-synacor-zimbra-collaboration-suite-xss-in-classic-web-client)