Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2022-10-20
• Known to be used in ransomware campaigns
• EPSS: 95% chance of exploitation in the next 30 days (higher than 100% of CVEs)
• Critical severity: CVSS 9.8

[ Description ]Official description

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.

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

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 10 Nov 2022): Apply updates per vendor instructions.

• Patch on wiki.zimbra.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD

[ References ]References

• packetstormsecurity.com/files/169458/Zimbra-Collaboration-Suite-TAR-Path-Traversal.htmlExploitThird Party AdvisoryVDB Entry
• forums.zimbra.org/viewtopic.phpMitigationVendor Advisory
• wiki.zimbra.com/wiki/Security_CenterPatchRelease NotesVendor Advisory
• wiki.zimbra.com/wiki/Zimbra_Security_AdvisoriesVendor Advisory
• www.secpod.com/blog/unpatched-rce-bug-in-zimbra-collaboration-suite-exploited-in-wildThird Party Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource