Vulnerability record

CVE-2022-37042

Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass Vulnerability

CriticalExploitation confirmedCISA KEV Used by ransomware

What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run Zimbra Collaboration Suite (ZCS), fix it now.

CISA required action: Apply updates per vendor instructions.

US federal civilian agencies must remediate by Sep 1, 2022.

Patch status

Official fix available since Sep 30, 2026

Apply the vendor's update to every affected system. Check the fixed-in versions below where known.

Basis: NVD patch reference

Patch or advisory on wiki.zimbra.com (opens in a new tab)

Description

Zimbra Collaboration Suite (ZCS) 8.8.15 and 9.0 has mboximport functionality that receives a ZIP archive and extracts files from it. By bypassing authentication (i.e., not having an authtoken), an attacker can upload arbitrary files to the system, leading to directory traversal and remote code execution. NOTE: this issue exists because of an incomplete fix for CVE-2022-27925.

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

Products affected by this vulnerability, with versions and the source of each entry
Product	Vendor	Affected versions	Source
Zimbra Collaboration Suite	Synacor	8.8.15; 9.0.0	NVD
Zimbra Collaboration Suite (ZCS)	Synacor	—	KEV

Sources: NVD = NIST National Vulnerability Database; KEV = CISA Known Exploited Vulnerabilities catalog.

Intelligence timeline

Developments from the last 30 days, newest first.

CVSS scoredUpdateKEVSep 30, 2026
CVE-2022-37042 scored CVSS 9.8: Synacor Zimbra Collaboration Suite (ZCS), Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass Vulnerability
CISA lists this as exploited in the wild and known to be used in ransomware campaigns. Unpatched Zimbra Collaboration Suite (ZCS) systems are exposed to active attacks now.
Basis: NIST National Vulnerability Database
Patch releasedUpdateKEVSep 30, 2026
Patch released for CVE-2022-37042: Synacor Zimbra Collaboration Suite (ZCS), Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass Vulnerability
An official fix is now available for Synacor Zimbra Collaboration Suite (ZCS). This vulnerability is being exploited, so apply it promptly.
Basis: NVD patch reference

1 earlier event is available with a subscription. See plans.

Coverage

We have not published a story about this vulnerability yet.

References

blog.zimbra.com https://blog.zimbra.com/2022/08/authentication-bypass-in-mailboximportservlet-vulnerability/
nvd.nist.gov https://nvd.nist.gov/vuln/detail/CVE-2022-37042
packetstormsecurity.com http://packetstormsecurity.com/files/168146/Zimbra-Zip-Path-Traversal.html
wiki.zimbra.com https://wiki.zimbra.com/wiki/Security_Center
wiki.zimbra.com https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-37042