Executive Risk Summary
"A remote attacker can cause excessive CPU consumption in ASP.NET Core Kestrel by sending a crafted QUIC packet, potentially leading to a denial-of-service condition. This vulnerability affects Microsoft .NET 8.0 before 8.0.22 and .NET 9.0 before 9.0.11."
Anticipated Attack Path
- 1. An attacker sends a crafted QUIC packet to the vulnerable ASP.NET Core Kestrel server.
- 2. The server's HTTP/3 Encoder/Decoder stream processing fails to exit correctly, leading to excessive CPU consumption.
- 3. The server becomes unresponsive or experiences significant performance degradation, resulting in a denial-of-service condition.
Am I Vulnerable?
- Is your ASP.NET Core Kestrel server running on Microsoft .NET 8.0 before 8.0.22 or .NET 9.0 before 9.0.11?
- Are your servers exposed to the internet or accessible by untrusted users?
- Have you applied the latest security patches to your .NET installations?
Operational Audit Arsenal
Target Type Web Server
Target Asset ASP.NET Core Kestrel
Standard Path Management Plane / Web UI
PowerShell
# 🛠️ Senior Engineer Universal Audit
# Target: ASP.NET Core Kestrel (Web Server)
$Targets = 'ASP.NET Core Kestrel'
$SearchPaths = @("$env:windir\System32", "$env:ProgramFiles", "${env:ProgramFiles(x86)}")
Get-ChildItem -Path $SearchPaths -Include $Targets -Recurse -ErrorAction SilentlyContinue |
Select-Object FullName, @{Name="Version";Expression={$_.VersionInfo.ProductVersion}}Patch Impact Forecast
Reboot Required Unlikely
Minimal, as the patch can be applied during a maintenance window without significant downtime.
Internal Work Notes
Potential DoS vulnerability in ASP.NET Core Kestrel, recommend patching to .NET 8.0.22 or .NET 9.0.11 to mitigate risk.
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Intelligence Sources
Related Microsoft Threats
Data compiled from NVD, MSRC, and CISA KEV Catalog. Intelligence synthesized via AI. Scripts provided for diagnostic purposes under MIT License.