Windows 10 1507Operating system · Microsoft

CVE-2016-7255

HIGH · 7.8 CVSS v3.1 Published 2016-11-10

Patch available

A vendor patch is available. No clean upgrade release — apply the published patch.

See remediation →

97/100

Remediation priority · Urgent

In the wild High EPSS Public exploit No privileges Patch available

Official description

NVD · unedited

The kernel-mode drivers in 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, Windows 10 Gold, 1511, and 1607, and Windows Server 2016 allow local users to gain privileges via a crafted application, aka "Win32k Elevation of Privilege Vulnerability."

Technical summary

dbcve analysis · high confidence

CVE-2016-7255 is an elevation of privilege vulnerability in the Win32k kernel-mode driver (win32k.sys) affecting Windows Vista SP2 through Windows Server 2016. The vulnerability allows a local authenticated attacker to execute arbitrary code in kernel mode by leveraging improper handling of window objects in the win32k subsystem, bypassing the sandbox and gaining elevated privileges.

MitigationApply Microsoft security update KB3199135 (MS16-135) to all affected Windows systems, or deploy the Cumulative Security Update for November 2016 which contains the fix.

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

Affected products & versions

NVD · CPE data

Windows 10 1507Operating system

Affected:all versions

Windows 10 1511Operating system

Affected:all versions

Windows 10 1607Operating system

Affected:all versions

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

CVSS breakdown

From the vector

Attack vector: Local
Complexity: Low
Privileges: None
User interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

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

Am I affected?

dbcve checks

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

Identify Windows version

Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to determine the exact Windows version and build number

Affected if The version is Windows 10 1507/1511/1607, Windows 7, Windows 8.1, Windows Rt 8.1, Windows Server 2008/2008 R2, Windows Server 2012/2012 R2, or Windows Server 2016
Verify KB3199135 patch status

Run 'wmic qfe list | findstr "3199135"' or check Windows Update history for the presence of security update KB3199135

Affected if The security update KB3199135 is NOT installed or not listed in installed updates
Alternative: Check November 2016 cumulative update

Run 'wmic qfe list' and search for any November 2016 security update (typically KB3200970 or similar monthly rollups)

Affected if No November 2016 or later cumulative security update is installed on systems that received monthly rollups instead of standalone KB3199135
Inspect win32k.sys version as secondary check

Locate win32k.sys in C:\Windows\System32\ and check its file version property, or run 'driverquery /v | findstr win32k'

Affected if The driver version is older than the patched version for the respective Windows build and the patch is not present

You are affected if you run any affected Windows version (Vista SP2 through Windows Server 2016) AND the security update KB3199135 or November 2016 cumulative update is not installed.

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

Remediation

dbcve · scoped

Patch available Apply the vendor patch

Vendor patch docs.microsoft.com →

Interim mitigation

Apply Microsoft security update KB3199135 (MS16-135) to all affected Windows systems, or deploy the Cumulative Security Update for November 2016 which contains the fix.

Recommended fix High confidence

Install Microsoft November 2016 Security Updates (MS16-135) - contact Microsoft Update Catalog for version-specific KB articles (KB3197869 for Win7, KB3200970 for Win10, KB3201627 for Win8.1/Server 2012)

Verify the current Windows version by running 'winver' or 'systeminfo' in Command Prompt
Check if the system has received the November 2016 security updates (KB3197869 for Windows 7 SP1, KB3200970 for Windows 10, or equivalent for other versions)
Open Windows Update (Start > Settings > Update & Security > Windows Update)
Click 'Check for updates' and install all available security updates
If updates are managed via group policy or WSUS, ensure the November 2016 security updates (MS16-135) are deployed
After patching, verify the win32k.sys version matches the patched version (e.g., 10.0.14393.0 or later for Windows 10 1607)
Reboot the system as required to complete the update installation

Caveat This is a kernel-level security patch; ensure critical systems are tested in a staging environment before broad deployment; some updates may require reboot

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 10 1507 Exploited in the wild — priority engagement

Consultation4.0 h
Implementation8.0 h
Testing6.0 h
Review / QA4.0 h

22.0 hours of engineering $3,860

Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

Scan for this in your stack

Free · runs locally

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References

Primary sources

docs.microsoft.comPatch / commit
packetstormsecurity.comProof of Concept
docs.microsoft.comPatchVendor Advisory
packetstormsecurity.comExploitThird Party AdvisoryVDB Entry
www.securityfocus.comBroken LinkThird Party AdvisoryVDB Entry
www.securitytracker.comBroken LinkThird Party AdvisoryVDB Entry
github.comExploitThird Party Advisory
security.googleblog.comThird Party Advisory
www.exploit-db.comExploitThird Party AdvisoryVDB Entry
www.exploit-db.comExploitThird Party AdvisoryVDB Entry
www.exploit-db.comExploitThird Party AdvisoryVDB Entry
blog.trendmicro.comBroken Link
securingtomorrow.mcafee.comBroken Link
www.cisa.govUS Government Resource
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-7255 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2016-7255?

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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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

At a glance

Exploited in the wildOn CISA’s known-exploited list · agencies must fix by 2022-05-03

A fix existsA vendor remedy is published

Severity 7.8 High

Exploit likelihood EPSS, next 30 days 81.0%

Affects: Windows 10 1507

Remediation

Being exploited — close it fast

Fix this in Windows 10 1507 22 hrs · Moderate

Typical engagement from $3,860

Get it fixed fast See the full breakdown ↓

This CVE is on CISA’s actively-exploited list, so the clock is real — a vetted specialist can deliver a reviewed fix for your staging environment quickly.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

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.

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.

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.

Check your environment

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.

Scan for this in your stack

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

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References