dbcve.org
Windows 10Operating system · Microsoft

CVE-2016-3299

MEDIUM · 5.3 CVSS v3.0 Published 2016-08-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
60/100
Remediation priority · Elevated
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
Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511 allow remote attackers to hijack network traffic or bypass intended Enhanced Protected Mode (EPM) or application container protection mechanisms, and consequently render untrusted content in a browser, by leveraging how NetBIOS validates responses, aka "NetBIOS Spoofing 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 · high confidence

This vulnerability exists in how Windows validates NetBIOS responses, allowing remote attackers to spoof NetBIOS name resolution and hijack network traffic. The flaw enables bypassing Enhanced Protected Mode (EPM) and application container protections in browsers, permitting untrusted content to render in a protected context.

MitigationApply the Microsoft security update (MS16-101) for this vulnerability. Additionally, disable NetBIOS over TCP/IP on systems where it's not required, or enforce SMB signing at the network level to prevent NetBIOS spoofing 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
Windows 10Operating system
Affected:all versions= 1511= 1607
Windows 7Operating system
Affected:all versions
Windows 8.1Operating system
Affected:all versions
Windows Rt 8.1Operating system
Affected:all versions
Windows Server 2008Operating system
Affected:all versions= r2
Windows Server 2012Operating system
Affected:all versions= r2
Windows VistaOperating system
Affected:all versions

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
High
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/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. Check Windows version
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to identify the installed Windows version and build number
    Affected if The version is Windows Vista, 7, 8.1, RT 8.1, 10 (any build), Server 2008, Server 2008 R2, Server 2012, or Server 2012 R2
  2. Verify NetBIOS over TCP/IP is enabled
    Open Network Connections, right-click the active network adapter, select Properties, double-click Internet Protocol Version 4 (TCP/IPv4), click Advanced, then check the WINS tab. Alternatively, run 'reg query "HKLM\SYSTEM\CurrentControlSet\Services\NetBT\Parameters\Interfaces\Tcpip_*" /v NetbiosOptions'
    Affected if NetBIOS over TCP/IP is set to Enabled (value 0x0) or Use LMHOSTS lookup - the vulnerability exploits NetBIOS response validation, so enabled NetBIOS is required for exploitation
  3. Confirm MS16-101 security update is installed
    Run 'wmic qfe list hotfixid' or check Windows Update history for security update KB3178465 (for client) or KB3178466 (for server)
    Affected if The security update KB3178465 or KB3178466 is NOT installed - the system remains vulnerable to NetBIOS response spoofing
  4. Check Enhanced Protected Mode status in Internet Explorer
    Open Internet Explorer, go to Internet Options > Security tab, select the Internet zone, and check if 'Enable Enhanced Protected Mode' is checked. Also check under 'Advanced' > 'Security' section
    Affected if Enhanced Protected Mode is enabled AND NetBIOS is enabled AND the system lacks the patch - the vulnerability specifically allows bypassing this protection

A system is affected if it runs any affected Windows version listed, has NetBIOS over TCP/IP enabled, and is missing the MS16-101 security update (KB3178465 or KB3178466).

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

Apply the Microsoft security update (MS16-101) for this vulnerability. Additionally, disable NetBIOS over TCP/IP on systems where it's not required, or enforce SMB signing at the network level to prevent NetBIOS spoofing attacks.

Fix this in Windows 10 Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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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-2016-3299 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