Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability (CVE-2022-41352)

Synacor Zimbra Collaboration Suite (ZCS) allows an attacker to upload arbitrary files using cpio package to gain incorrect access to any other user accounts.

Published Sep 26, 2022 · Updated May 29, 2026

X LinkedIn

Why patchRisk explained in plain English

Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2022-11-10 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Path Traversal (CWE-22) vulnerability in Synacor Zimbra Collaboration Suite (ZCS). An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0. An attacker can upload arbitrary files through amavis via a cpio loophole (extraction to /opt/zimbra/jetty/webapps/zimbra/public) that can lead to incorrect access to any other user accounts. Zimbra recommends pax over cpio. Also, pax is in the prerequisites of Zimbra on Ubuntu; however, pax is no longer part of a default Red Hat installation after RHEL 6 (or CentOS 6). Once pax is installed, amavis automatically prefers it over cpio. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

📧

Phishing link

→

🖼

Malicious file

🔓

Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

●IT Security

●Running zimbra collaboration suite: 9.0.0, 8.8.15

Real-world incidentsWhat we've seen

Active exploitation documented in the wild. Threat-research write-up: http://packetstormsecurity.com/files/169458/Zimbra-Collaboration-Suite-TAR-Path-Traversal.html

How to patch

Get the fix

Apply the fixed package from your vendor. The advisory lists affected versions and the exact fixed build.

↗ Vendor advisory

Manual remediation steps