CVE-2016-3379
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 · uneditedCross-site scripting (XSS) vulnerability in Microsoft Exchange Server 2016 Cumulative Update 1 and 2 allows remote attackers to inject arbitrary web script or HTML via a meeting-invitation request, aka "Microsoft Exchange Elevation of Privilege Vulnerability."
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 confidenceCross-site scripting (XSS) vulnerability in Microsoft Exchange Server 2016 CU1 and CU2 allows remote attackers to inject arbitrary web script or HTML via specially crafted meeting-invitation requests, enabling elevation of privilege attacks.
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= 2016CVSS 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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Identify Exchange Server versionOpen Exchange Management Shell and run Get-ExchangeServer | Format-List Name,Edition,AdminDisplayVersion,OU,ServerRoleAffected if The version shown is Microsoft Exchange Server 2016 Cumulative Update 1 or Cumulative Update 2
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Check Exchange build numberRun Get-ExchangeServer | Select-Object Name, AdminDisplayVersion in Exchange Management Shell to see the full build number (e.g., 15.1.xxxx)Affected if The build number corresponds to Exchange 2016 CU1 (15.1.225) or CU2 (15.1.466)
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Verify meeting invitation feature is enabledConfirm Exchange Server is configured to process meeting requests. This is the default configuration in Exchange 2016; check via Get-CalendarProcessing or review if Outlook Web App (OWA) or Outlook Anywhere accepts meeting invitationsAffected if Meeting processing is enabled (default state) on a vulnerable Exchange 2016 CU1/CU2 server
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Check if OWA or ECP is accessibleVerify that Outlook Web App or Exchange Control Panel is accessible as these are vectors for the XSS through meeting invitationsAffected if OWA/ECP is enabled and accessible on an affected Exchange 2016 version
A user is affected if their Microsoft Exchange Server 2016 is running Cumulative Update 1 or Cumulative Update 2, with meeting invitation processing enabled (the default configuration).
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 dataApply Microsoft security updates to Exchange Server 2016 or upgrade to a later cumulative update that addresses this vulnerability. Additionally, implement input validation on meeting invitation processing as a defense-in-depth measure.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,464.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-3379 — 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-2016-3379 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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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.
- 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