Microsoft Windows up to Server 2019 WalletService memory corruption

Summaryinfo

A vulnerability marked as critical has been reported in Microsoft Windows. Impacted is an unknown function of the component WalletService. The manipulation leads to memory corruption. This vulnerability is uniquely identified as CVE-2020-1556. Local access is required to approach this attack. No exploit exists. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Microsoft Windows (Operating System). This issue affects an unknown code of the component WalletService. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

An elevation of privilege vulnerability exists in the way that the Windows WalletService handles objects in memory. An attacker who successfully exploited the vulnerability could execute code with elevated permissions. To exploit the vulnerability, a locally authenticated attacker could run a specially crafted application. The security update addresses the vulnerability by ensuring the Windows WalletService properly handles objects in memory.

The weakness was disclosed 08/11/2020 as confirmed security update guide (Website). It is possible to read the advisory at portal.msrc.microsoft.com. The public release has been coordinated in cooperation with Microsoft. The identification of this vulnerability is CVE-2020-1556. Attacking locally is a requirement. A simple authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 02/24/2026). The advisory points out:

An elevation of privilege vulnerability exists in the way that the Windows WalletService handles objects in memory. An attacker who successfully exploited the vulnerability could execute code with elevated permissions.

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

The entries VDB-159531, VDB-159530, VDB-159529 and VDB-159528 are pretty similar. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Microsoft

Name

• Windows

Version

• 10
• 10 1607
• 10 1709
• 10 1803
• 10 1809
• 10 1903
• 10 1909
• 10 2004
• Server 1903
• Server 1909
• Server 2004
• Server 2016
• Server 2019

License

• commercial

Website

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

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