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

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: yes — in CISA KEV since 2022-01-10
EPSS: 100.0% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2019-05-29 · updated 2026-06-17
Weakness: CWE-611

Description

mailboxd component in Synacor Zimbra Collaboration Suite 8.7.x before 8.7.11p10 has an XML External Entity injection (XXE) vulnerability, as demonstrated by Autodiscover/Autodiscover.xml.

Affected products

Zimbra Collaboration: from 8.7.0 before 8.7.11; 8.7.11, 8.7.11-p1, 8.7.11-p2, 8.7.11-p3, 8.7.11-p4, 8.7.11-p5 (+4) — fixed in 8.7.11

How to fix

Upgrade to a fixed version: Zimbra Collaboration 8.7.11. Check the vendor advisory for mitigations.

References

http://packetstormsecurity.com/files/152487/Zimbra-Collaboration-Autodiscover-Servlet-XXE-ProxyServlet-SSRF.html
http://www.rapid7.com/db/modules/exploit/linux/http/zimbra_xxe_rce
https://bugzilla.zimbra.com/show_bug.cgi?id=109129
https://isc.sans.edu/forums/diary/CVE20199670+Zimbra+Collaboration+Suite+XXE+vulnerability/27570/
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
https://www.exploit-db.com/exploits/46693/
http://packetstormsecurity.com/files/152487/Zimbra-Collaboration-Autodiscover-Servlet-XXE-ProxyServlet-SSRF.html
http://www.rapid7.com/db/modules/exploit/linux/http/zimbra_xxe_rce
https://bugzilla.zimbra.com/show_bug.cgi?id=109129
https://isc.sans.edu/forums/diary/CVE20199670+Zimbra+Collaboration+Suite+XXE+vulnerability/27570/
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
https://www.exploit-db.com/exploits/46693/

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