Overview
.NET is a free, open-source, cross-platform framework for building modern apps and powerful cloud services. It consists of a runtime and a developer platform made up of tools, programming languages, and libraries for building many different types of applications.
A vulnerability (CVE-2025-21176) exists in DiaSymReader.dll due to buffer over-read. Insufficient input validation in Visual Studio allows remote code execution via crafted files. An attacker could exploit this vulnerability by loading a specially crafted file in Visual Studio.
Per CWE-126: Buffer Over-read, Buffer Over-read is when a product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.
This issue affects .NET 6.0.0 <= 6.0.36, 8.0.0 <= 8.0.11, <= 9.0.0.
Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.
Details
Module Info
- Product:
- Any .NET 6.0 application running on .NET 6.0.36 or earlier.
- Any .NET 8.0 application running on .NET 8.0.11 or earlier.
- Any .NET 9.0 application running on .NET 9.0.0 or earlier.
- Affected packages:
- Microsoft.NetCore.App.Runtime.linux-arm
- Microsoft.NetCore.App.Runtime.linux-arm64
- Microsoft.NetCore.App.Runtime.linux-musl-arm
- Microsoft.NetCore.App.Runtime.linux-musl-arm64
- Microsoft.NetCore.App.Runtime.linux-musl-x64
- Microsoft.NetCore.App.Runtime.linux-x64
- Microsoft.NetCore.App.Runtime.osx-arm64
- Microsoft.NetCore.App.Runtime.osx-x64
- Microsoft.NetCore.App.Runtime.win-arm
- Microsoft.NetCore.App.Runtime.win-arm64
- Microsoft.NetCore.App.Runtime.win-x64
- Microsoft.NetCore.App.Runtime.win-x86
- Affected versions:
- >= 6.0.0 <= 6.0.36
- >= 8.0.0 <= 8.0.11
- <= 9.0.0
- GitHub repository: https://github.com/dotnet
- Published packages: Download .NET (Linux, macOS, and Windows)
- Package manager:
- Nuget
- Windows Installer
- Docker
- Fixed in: .NET - Never-Ending Support (NES) | HeroDevs v6.1.0
Vulnerability Info
This High-severity vulnerability is found in DiaSymReader.dll. Insufficient input validation in Visual Studio allows remote code execution via crafted files. Exploitation of this vulnerability requires that an attacker convinces a user to open a maliciously crafted package file in Visual Studio.
Credits
- goodbyeselene
Mitigation
.NET 6.x is End-of-Life and will not receive any updates to address this issue. For more information see .NET and .NET Core official support policy.
Users of the affected components should apply one of the following mitigations:
- Upgrade affected applications to one of:
- .NET Runtime >= 8.0.12
- .NET Runtime >= 9.0.1
- Leverage a commercial support partner like HeroDevs for post-EOL security support.
