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Known exploited · Synacor

CVE-2022-27925: Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability

What it is

Synacor Zimbra Collaboration Suite (ZCS) contains flaw in the mboximport functionality, allowing an authenticated attacker to upload arbitrary files to perform remote code execution. This vulnerability was chained with CVE-2022-37042 which allows for unauthenticated remote code execution.

Added August 11, 2022Due September 1, 2022CISA KEV catalog 2026.10.01

Vendor
Synacor
Product
Zimbra Collaboration Suite (ZCS)
Added to KEV
August 11, 2022
CISA due date
September 1, 2022
Ransomware use
Known

What CISA requires

Apply updates per vendor instructions.

Forensic triage

No

What to do now

  1. Find every instance of Zimbra Collaboration Suite (ZCS) you run, including the forgotten ones, and check its version against the vendor advisory.
  2. Apply the vendor's fix or mitigation, before September 1, 2022 if you are bound by CISA's deadline, sooner if it faces the internet.
  3. Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
  4. Until every instance is patched, block the attack at the edge: a WAF in blocking mode stops path traversal attempts.

References

CVE-2022-27925 in the National Vulnerability Database

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The Dome's WAF runs the OWASP Core Rule Set in blocking mode and stops path traversal attempts before they reach your application.

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Source: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.