HOMEVULNERABILITIESCVE-2018-20160
CRITICAL

CVE-2018-20160

CWE-611Published: May 29, 2019· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

ZxChat (aka ZeXtras Chat), as used for zimbra-chat and zimbra-talk in Synacor Zimbra Collaboration Suite 8.7 and 8.8 and in other products, allows XXE attacks, as demonstrated by a crafted XML request to mailboxd.

NVD Source

Technical Analysis

CVE-2018-20160 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

synacor1 product(s)
zimbra collaboration suite
Source: NVD CPE · 5 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://bugzilla.zimbra.com/show_bug.cgi?id=109093
ADVISORYhttps://wiki.zimbra.com/wiki/Security_Center
ADVISORYhttps://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
ADVISORYhttps://bugzilla.zimbra.com/show_bug.cgi?id=109093
ADVISORYhttps://wiki.zimbra.com/wiki/Security_Center
ADVISORYhttps://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

All References (6)

→
https://bugzilla.zimbra.com/show_bug.cgi?id=109093Issue Tracking · Third Party Advisory
→
https://wiki.zimbra.com/wiki/Security_CenterRelease Notes · Vendor Advisory
→
https://wiki.zimbra.com/wiki/Zimbra_Security_AdvisoriesVendor Advisory
→
https://bugzilla.zimbra.com/show_bug.cgi?id=109093Issue Tracking · Third Party Advisory
→
https://wiki.zimbra.com/wiki/Security_CenterRelease Notes · Vendor Advisory
→
https://wiki.zimbra.com/wiki/Zimbra_Security_AdvisoriesVendor Advisory

Quick Facts

CVE IDCVE-2018-20160
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-611
CISA KEVNo
Affected1 vendor(s)
PublishedMay 29, 2019

Related CVEs (CWE-611)

CVE-2019-14678
10.0
CVE-2023-38490
10.0
CVE-2018-1000820
10.0
CVE-2018-1000652
10.0
CVE-2017-8110
10.0
CVE-2018-1000644
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2018-20160 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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