Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains an authentication bypass vulnerability in MailboxImportServlet. This vulnerability was chained with CVE-2022-27925 which allows for unauthenticated remote code execution.
A remote attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. CISA has confirmed use of this vulnerability in known ransomware campaigns — treat as high priority for remediation. Federal agencies are required to remediate by 2022-09-01 under CISA BOD 22-01.
This is a Path Traversal (CWE-22) vulnerability in Synacor Zimbra Collaboration Suite (ZCS). Zimbra Collaboration Suite (ZCS) 8.8.15 and 9.0 has mboximport functionality that receives a ZIP archive and extracts files from it. By bypassing authentication (i.e., not having an authtoken), an attacker can upload arbitrary files to the system, leading to directory traversal and remote code execution. NOTE: this issue exists because of an incomplete fix for CVE-2022-27925. 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:
Used in known ransomware campaigns. Threat-research write-up: http://packetstormsecurity.com/files/168146/Zimbra-Zip-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