Microsoft Windows up to Server 2019 Win32k access control

CVSS Meta Temp Score
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CTI Interest Score
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7.7$5k-$25k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Microsoft Windows. This affects an unknown function of the component Win32k. Executing a manipulation can lead to access control. This vulnerability appears as CVE-2018-8639. The attack may be performed from remote. In addition, an exploit is available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability classified as critical was found in Microsoft Windows (Operating System). This vulnerability affects an unknown functionality of the component Win32k. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-264. As an impact it is known to affect confidentiality, integrity, and availability.

The bug was discovered 12/11/2018. The weakness was presented 12/11/2018 by Appsec as confirmed security update guide (Website). The advisory is shared for download at portal.msrc.microsoft.com. The public release was coordinated in cooperation with the vendor. This vulnerability was named CVE-2018-8639 since 03/14/2018. The attack can be initiated remotely. The successful exploitation needs a single authentication. Technical details are unknown but an exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 04/07/2025). The MITRE ATT&CK project declares the attack technique as T1068. The advisory points out:

An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

It is declared as attacked. The vulnerability scanner Nessus provides a plugin with the ID 119591 (KB4471332: Windows 10 Version 1809 and Windows Server 2019 December 2018 Security Update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Windows : Microsoft Bulletins and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 91488 (Microsoft Windows Security Update December 2018). This issue was added on 03/03/2025 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 03/24/2025:

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (119591) and SecurityFocus (BID 106093†). See VDB-127795, VDB-127796, VDB-127797 and VDB-127798 for similar entries. Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 7.0
Vendor Vector (Microsoft): 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-264
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Attacked

EPSS Score: 🔍
EPSS Percentile: 🔍

KEV Added: 🔍
KEV Due: 🔍
KEV Remediation: 🔍
KEV Ransomware: 🔍
KEV Notice: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 119591
Nessus Name: KB4471332: Windows 10 Version 1809 and Windows Server 2019 December 2018 Security Update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Timelineinfo

03/14/2018 🔍
12/11/2018 +272 days 🔍
12/11/2018 +0 days 🔍
12/11/2018 +0 days 🔍
12/11/2018 +0 days 🔍
12/11/2018 +0 days 🔍
12/11/2018 +0 days 🔍
12/12/2018 +1 days 🔍
04/07/2025 +2308 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: portal.msrc.microsoft.com
Researcher: Appsec
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍

CVE: CVE-2018-8639 (🔍)
GCVE (CVE): GCVE-0-2018-8639
GCVE (VulDB): GCVE-100-127828
SecurityFocus: 106093 - Microsoft Windows Kernel 'Win32k.sys' CVE-2018-8639 Local Privilege Escalation Vulnerability

scip Labs: https://www.scip.ch/en/?labs.20161215
See also: 🔍

Entryinfo

Created: 12/12/2018 08:11
Updated: 04/07/2025 18:05
Changes: 12/12/2018 08:11 (86), 04/20/2020 07:00 (6), 06/18/2023 09:20 (4), 03/03/2025 18:36 (16), 03/04/2025 01:42 (13), 04/07/2025 18:05 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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