CVE-2018-18631
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 · uneditedmailboxd component in Synacor Zimbra Collaboration Suite 8.6, 8.7 before 8.7.11 Patch 7, and 8.8 before 8.8.10 Patch 2 has Persistent XSS.
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 · high confidencePersistent XSS vulnerability in the mailboxd component of Synacor Zimbra Collaboration Suite allows attackers to inject malicious scripts that persist and execute when other users view the compromised content.
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>= 8.7.0, < 8.7.11>= 8.8.0, < 8.8.9= 8.6.0= 8.7.11= 8.8.9= 8.8.10CVSS 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:3.0/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 checksWork through these to decide whether this CVE applies to you.
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Check Zimbra Collaboration Suite versionRun 'zmcontrol -v' or 'zmcontrol status' as the zimbra user to determine the installed version. Alternatively, inspect /opt/zimbra/.version_info or query the installed package via 'rpm -q zimbra-common-core-jar'Affected if The displayed version falls within any of these ranges: 8.6.0, >= 8.7.0 through 8.7.10, 8.7.11, >= 8.8.0 through 8.8.9, 8.8.10 (meaning versions 8.6.0, 8.7.0-8.7.11, and 8.8.0-8.8.10 are all affected)
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Verify mailboxd component is presentRun 'zmcontrol status' or check if the mailboxd service is listed as running. This component is included in the standard Zimbra Collaboration Suite installation and handles mail storage and processing.Affected if The mailboxd service exists and is enabled in the Zimbra environment (this is required for the vulnerability to be exploitable)
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Confirm the installation type excludes patched versionsReview the exact version number. Note that 8.7.11 and 8.8.10 ARE affected per the version list, but fully patched systems would have applied the vendor patches on top of these base versions.Affected if The system is running an affected version without the cumulative vendor patch applied (8.7.11 Patch 7 or 8.8.10 Patch 2)
You are affected if your Zimbra Collaboration Suite installation runs version 8.6.0, 8.7.x through 8.7.11, or 8.8.x through 8.8.10, and the mailboxd component is enabled, without the vendor-supplied security patches applied.
Generated from the published advisory. Verify against your own configuration.
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 data8.7.118.8.9
Apply the vendor-supplied patches (8.7.11 Patch 7 for 8.7.x or 8.8.10 Patch 2 for 8.8.x) to address the persistent cross-site scripting vulnerability in the mailboxd component.
- Consultation3.0 h
- Implementation6.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-18631 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-18631 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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