Microsoft Windows up to Server 2019 Symlink access control

Summaryinfo

A vulnerability identified as critical has been detected in Microsoft Windows. This vulnerability affects unknown code of the component Symlink Handler. This manipulation causes access control. This vulnerability is handled as CVE-2019-0936. The attack can be initiated remotely. There is not any exploit available. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability classified as critical was found in Microsoft Windows (Operating System). Affected by this vulnerability is some unknown functionality of the component Symlink Handler. 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 summary by CVE is:

An elevation of privilege vulnerability exists in Microsoft Windows when Windows fails to properly handle certain symbolic links, aka 'Windows Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2019-0734.

The bug was discovered 05/14/2019. The weakness was released 05/14/2019 as confirmed security update guide (Website). It is possible to read the advisory at portal.msrc.microsoft.com. The public release was coordinated with Microsoft. This vulnerability is known as CVE-2019-0936 since 11/26/2018. The attack can be launched remotely. A single authentication is required for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/11/2024). The attack technique deployed by this issue is T1068 according to MITRE ATT&CK. The advisory points out:

An elevation of privilege vulnerability exists in Microsoft Windows when Windows fails to properly handle certain symbolic links. An attacker who successfully exploited this vulnerability could potentially set certain items to run at a higher level and thereby elevate permissions.

The commercial vulnerability scanner Qualys is able to test this issue with plugin 91529 (Microsoft Windows Security Update for May 2019).

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

Entries connected to this vulnerability are available at VDB-134733 and VDB-134729. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Microsoft

Name

• Windows

Version

• 7 SP1
• 8.1
• 10
• 10 1607
• 10 1703
• 10 1709
• 10 1803
• 10 1809
• 10 1903
• RT 8.1
• Server 1803
• Server 1903
• Server 2008 R2 SP1
• Server 2008 SP2
• Server 2012
• Server 2012 R2
• Server 2016
• Server 2019

License

• commercial

Website

• Vendor: https://www.microsoft.com/
• Product: https://www.microsoft.com/en-us/windows

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Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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