mailboxd component in Synacor Zimbra Collaboration Suite 8.7.x before 8.7.11p10 has an XML External Entity injection (XXE) vulnerability, a…

published 2019-05-29 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-19036

cvss: 9.8; version 3.1, CNA
cisa kev: Exploited; added 2022-01-10
epss: 100.0%; EPSS 100.0% chance of exploitation in 30 days, percentile 99.9%
public exploits: 2; Metasploit, Exploit-DB, plus a Nuclei check

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.

Patch / fix

cisa required action Apply updates per vendor instructions.

fixed in 1 links 1

synacor zimbra_collaboration_suite 8.7.11

bugzilla.zimbra.com/show_bug.cgi?id=109129 advisory

Timeline

2019-03-13 First public exploit (Metasploit exploit/linux/http/zimbra_xxe_rce)
2019-05-29 Published
2022-01-10 Added to CISA KEV
2022-07-10 CISA patch deadline
2025-02-07 CISA SSVC: exploitation active

Known exploited

Added: 4 y ago (2022-01-10)
Patch by: 2022-07-10 (4 y ago)
Ransomware: Not known
Required action: Apply updates per vendor instructions.
Vendor, product: Synacor, Zimbra Collaboration Suite (ZCS)
CISA name: Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity Reference

CISA SSVC

Exploitation: Active, exploited in the wild
Automatable: yes
Technical impact: total
Assessed: 21 mo ago (2025-02-07)

Exploit prediction

99.99% chance of exploitation in the next 30 days, higher than 99.9% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

Metasploit exploit/linux/http/zimbra_xxe_rce Zimbra Collaboration Autodiscover Servlet XXE and ProxyServlet SSRF metasploit exploit, excellent rank, 2019-03-13
EDB-46693 Zimbra Collaboration - Autodiscover Servlet XXE and ProxyServlet SSRF (Metasploit) remote, 2019-04-12
Nuclei template Synacor Zimbra Collaboration <8.7.11p10 - XML External Entity Injection nuclei detection template
packetstormsecurity.com http://packetstormsecurity.com/files/152487/Zimbra-Collaboration-Autodiscover-Servlet-XXE-ProxyServlet-SSRF.html referenced PoC, tagged "exploit" by a source, unverified
isc.sans.edu https://isc.sans.edu/forums/diary/CVE20199670+Zimbra+Collaboration+Suite+XXE+vulnerability/27570/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness

CWE-611 Improper Restriction of XML External Entity Reference

References

bugzilla.zimbra.com /show_bug.cgi?id=109129
broken-link, issue-tracking, patch, third-party-advisory
exploit-db.com /exploits/46693/
exploit, third-party-advisory, vdb-entry
packetstormsecurity.com /files/152487/Zimbra-Collaboration-Autodiscover-Servlet-XXE-ProxyServlet-SSRF.html
exploit, third-party-advisory, vdb-entry
isc.sans.edu /forums/diary/CVE20199670+Zimbra+Collaboration+Suite+XXE+vulnerability/27570/
exploit, third-party-advisory
wiki.zimbra.com /wiki/Zimbra_Security_Advisories
vendor-advisory
rapid7.com /db/modules/exploit/linux/http/zimbra_xxe_rce
third-party-advisory
cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-9670
government-resource, us-government-resource

Sources

CVE List CVE-2019-9670
NVD CVE-2019-9670

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary