Zimbra Collaboration SuiteApplication · Synacor

CVE-2024-50599

MEDIUM · 6.1 CVSS v3.1 Published 2024-11-07
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
High EPSS Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A reflected Cross-Site Scripting (XSS) vulnerability has been identified in Zimbra Collaboration Suite (ZCS) 8.8.15, affecting one of the webmail calendar endpoints. This arises from improper handling of user-supplied input, allowing an attacker to inject malicious code that is reflected back in the HTML response.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A reflected Cross-Site Scripting (XSS) vulnerability exists in Zimbra Collaboration Suite 8.8.15's webmail calendar endpoint due to improper handling of user-supplied input. The vulnerability allows an attacker to inject malicious scripts that get reflected in the HTML response without proper sanitization or encoding.

MitigationImplement robust input validation and output encoding on the affected calendar endpoint to neutralize malicious script injection. If available, apply vendor-provided patches for ZCS 8.8.15.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Zimbra Collaboration SuiteApplication
Affected:= 8.8.15

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Zimbra Collaboration Suite version
    Run 'zmcontrol -v' or check the installed package version (e.g., 'rpm -q zimbra-core' or via package manager).
    Affected if The installed version is exactly 8.8.15.
  2. Verify webmail service is running
    Run 'zmcontrol status' and check that the 'mailboxd' service is running, or access the webmail URL (typically /zimbra/mail) to confirm it's reachable.
    Affected if Webmail is accessible and the server runs ZCS 8.8.15.
  3. Confirm calendar module is accessible
    Log into Zimbra Webmail as a user and navigate to the Calendar feature, or attempt to access the calendar endpoint directly via the webmail interface.
    Affected if The calendar feature is available and functional in the webmail interface.
  4. Inspect calendar endpoint for input reflection
    Use browser developer tools or a web proxy to submit a test query parameter to the calendar endpoint (e.g., parameters used when viewing or creating calendar events) and observe if the input is reflected in the response without encoding.
    Affected if User-supplied input in calendar-related requests is reflected in the HTML response without proper encoding (visible in the raw HTTP response).

You are affected if you are running ZCS 8.8.15, the webmail service is accessible, and the calendar endpoint reflects user input without sanitization in the response.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement robust input validation and output encoding on the affected calendar endpoint to neutralize malicious script injection. If available, apply vendor-provided patches for ZCS 8.8.15.

Fix this in Zimbra Collaboration Suite Scoped from the published advisory
  • Consultation3.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
17.0 hours of engineering $3,000
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-50599 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data