IRONSMITHINTEL
MEDIUMCVSS6.1
|
Actively Exploited
|CISA KEV|CVE-2023-37580|Auth: none — unauthenticated|Reboot: required|Manual only

Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability

Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability impacting the confidentiality and integrity of data.

Published Jul 31, 2023 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve partial data exposure, partial data tampering. Federal agencies are required to remediate by 2023-08-17 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Cross-Site Scripting (XSS) (CWE-79) vulnerability in Synacor Zimbra Collaboration Suite (ZCS). Zimbra Collaboration (ZCS) 8 before 8.8.15 Patch 41 allows XSS in the Zimbra Classic Web Client. Exploitation requires remote network access, low attack complexity, no authentication required, and user interaction required.

📧

Phishing link

→

🖼

Malicious file

🔓

Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

●IT Security
●Running zimbra collaboration suite: 8.8.0 ≤ v < 8.8.15, 8.8.15
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2023-07-27 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2023-08-17.

How to patch

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

    1
    Vendor advisory: https://wiki.zimbra.com/wiki/Security_Center
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2023-37580
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-37580
PowerShell automationComing soon

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References

↗ CVE-2023-37580↗ NVD↗ Vendor Advisory