Synacor Zimbra Collaboration Suite (ZCS) Command Execution Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains an unspecified vulnerability in the postjournal service that may allow an unauthenticated user to execute commands.
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 2024-10-24 under CISA BOD 22-01.
This is a OS Command Injection (CWE-78) vulnerability in Synacor Zimbra Collaboration Suite (ZCS). The postjournal service in Zimbra Collaboration (ZCS) before 8.8.15 Patch 46, 9 before 9.0.0 Patch 41, 10 before 10.0.9, and 10.1 before 10.1.1 sometimes allows unauthenticated users to execute commands. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.
📧
Phishing link
🖼
Malicious file
🔓
Server compromised
Probably yes if any of these apply:
Active exploitation documented in the wild. Threat-research write-up: https://blog.projectdiscovery.io/zimbra-remote-code-execution/
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 mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
References
No tested PowerShell script for this entry yet. We’re prioritising automation based on user demand.
References