Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) allows an attacker to upload arbitrary files using cpio package to gain incorrect access to any other user accounts.
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.
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.
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Phishing link
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Malicious file
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Server compromised
Probably yes if any of these apply:
Active exploitation documented in the wild. Threat-research write-up: http://packetstormsecurity.com/files/169458/Zimbra-Collaboration-Suite-TAR-Path-Traversal.html
Manual remediation steps
Apply the Vendor Patch
This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.
CISA required action: Apply updates per vendor instructions.
References
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References