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

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2022-10-20. EPSS: 95.5% chance of exploitation in the next 30 days.

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.

Affected products

• Synacor Zimbra Collaboration Suite: version 9.0.0 only; version 8.8.15 only

Published 2022-09-26. Last modified 2026-09-10.