Sql ServerApplication · Microsoft

CVE-2016-7253

HIGH · 8.8 CVSS v3.0 Published 2016-11-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

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
The agent in Microsoft SQL Server 2012 SP2, 2012 SP3, 2014 SP1, 2014 SP2, and 2016 does not properly check the atxcore.dll ACL, which allows remote authenticated users to gain privileges via unspecified vectors, aka "SQL Server Agent 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 · high confidence

The SQL Server Agent in Microsoft SQL Server 2012 SP2/SP3, 2014 SP1/SP2, and 2016 fails to properly validate the Access Control List (ACL) on atxcore.dll. This allows remote authenticated users to manipulate the DLL and escalate privileges to execute code with elevated permissions via the SQL Server Agent service context.

MitigationApply Microsoft security update MS16-136 (CVE-2016-7253) to affected SQL Server installations, or upgrade to a patched version. Verify ACL permissions on atxcore.dll after patching.

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
Sql ServerApplication
Affected:= 2012= 2014

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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. Identify installed SQL Server version
    Run query 'SELECT @@VERSION' in SQL Server Management Studio or use: sqlcmd -S localhost -E -Q 'SELECT @@VERSION'
    Affected if Version is SQL Server 2012 SP2/SP3, 2014 SP1/SP2, or 2016 (any build within these version ranges)
  2. Confirm SQL Server Agent service is in use
    Check if SQL Server Agent service exists and is running: Open Services.msc and look for 'SQL Server Agent (instance_name)', or run 'Get-Service *SQL*Agent*' in PowerShell
    Affected if SQL Server Agent service is present and running on the affected SQL Server version
  3. Locate atxcore.dll file
    Search for atxcore.dll in the SQL Server Binn directory. Typical paths: C:\Program Files\Microsoft SQL Server\MSSQLnn.INSTANCE_NAME\MSSQL\Binn\ or C:\Program Files\Microsoft SQL Server\MSSQLnn.MSSQLSERVER\MSSQL\Binn\ (nn is version number: 12 for 2014, 13 for 2016)
    Affected if atxcore.dll exists in the SQL Server Binn directory
  4. Inspect ACL on atxcore.dll
    Right-click atxcore.dll in File Explorer, go to Properties > Security tab, click Advanced. Check the 'Access' entries for permissions granted to users/groups. Alternatively, run 'icacls "path\to\atxcore.dll"' in Command Prompt
    Affected if Any non-privileged authenticated user has Write, Modify, or Full Control permissions on atxcore.dll (improper ACL that allows manipulation)

User is affected if running SQL Server 2012 SP2/SP3, 2014 SP1/SP2, or 2016 with SQL Server Agent enabled and atxcore.dll has overly permissive ACL allowing authenticated users to modify the DLL.

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 Microsoft security update MS16-136 (CVE-2016-7253) to affected SQL Server installations, or upgrade to a patched version. Verify ACL permissions on atxcore.dll after patching.

Fix this in Sql Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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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-2016-7253 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
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