Microsoft Windows Kernel win32k.sys NtSetWindowLongPtr Browser privileges management

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.6$5k-$25k0.00

A vulnerability was found in Microsoft Windows (Operating System) (the affected version is unknown). It has been rated as critical. Affected by this issue is the function NtSetWindowLongPtr in the library win32k.sys of the component Kernel. The manipulation with an unknown input leads to a privileges management vulnerability (Browser). Using CWE to declare the problem leads to CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. Impacted is confidentiality, integrity, and availability.

The weakness was published 10/31/2016 by Neel Mehta and Billy Leonard with Google as Disclosing vulnerabilities to protect users as confirmed blog post (Blog). The advisory is available at security.googleblog.com. The vendor was not involved in the coordination of the public release. The blog post contains:

On Friday, October 21st, we reported 0-day vulnerabilities (...) After 7 days, per our published policy for actively exploited critical vulnerabilities, we are today disclosing the existence of a remaining critical vulnerability in Windows for which no advisory or fix has yet been released. This vulnerability is particularly serious because we know it is being actively exploited.
Local access is required to approach this attack. A simple authentication is needed for exploitation. Technical details as well as a private exploit are known. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 07/07/2019). This vulnerability is assigned to T1068 by the MITRE ATT&CK project. The advisory points out:
The Windows vulnerability is a local privilege escalation in the Windows kernel that can be used as a security sandbox escape. It can be triggered via the win32k.sys system call NtSetWindowLongPtr() for the index GWLP_ID on a window handle with GWL_STYLE set to WS_CHILD.

It is declared as highly functional. The vulnerability was handled as a non-public zero-day exploit for at least 10 days. During that time the estimated underground price was around $25k-$100k.

The best possible mitigation is suggested to be Workaround. The blog post contains the following remark:

Chrome's sandbox blocks win32k.sys system calls using the Win32k lockdown mitigation on Windows 10, which prevents exploitation of this sandbox escape vulnerability.

docs.google.com is providing further details.

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
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CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 7.6

VulDB Base Score: 7.8
VulDB Temp Score: 7.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
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VulDB Reliability: 🔍

Exploitinginfo

Name: Browser
Class: Privileges management / Browser
CWE: CWE-269 / CWE-266
ATT&CK: T1068

Local: Yes
Remote: No

Availability: 🔍
Access: Private
Status: Highly functional
Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Workaround
Status: 🔍

0-Day Time: 🔍

Workaround: Google Chrome

Timelineinfo

10/21/2016 🔍
10/31/2016 +10 days 🔍
11/01/2016 +1 days 🔍
07/07/2019 +978 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: Disclosing vulnerabilities to protect users
Researcher: Neel Mehta, Billy Leonard
Organization: Google
Status: Confirmed
scip Labs: https://www.scip.ch/en/?labs.20161013
Misc.: 🔍

Entryinfo

Created: 11/01/2016 14:34
Updated: 07/07/2019 18:04
Changes: 11/01/2016 14:34 (58), 07/07/2019 18:04 (2)
Complete: 🔍

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