CVE-2018-8409 in ASP.NET Core
Summary
by MITRE
A denial of service vulnerability exists when System.IO.Pipelines improperly handles requests, aka "System.IO.Pipelines Denial of Service." This affects .NET Core 2.1, System.IO.Pipelines, ASP.NET Core 2.1.
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Analysis
by VulDB Data Team • 03/22/2020
The vulnerability identified as CVE-2018-8409 represents a critical denial of service flaw within the System.IO.Pipelines component of Microsoft's .NET Core framework. This issue specifically manifests when the pipeline handling mechanism fails to properly process incoming requests, creating a condition where malicious or malformed inputs can trigger system resource exhaustion and subsequent service unavailability. The vulnerability affects versions of .NET Core 2.1 and ASP.NET Core 2.1, making it particularly concerning for organizations maintaining these framework versions in production environments.
The technical root cause of this vulnerability lies in the improper handling of request processing within the System.IO.Pipelines library, which serves as a fundamental component for efficient data processing and communication in .NET applications. When the pipeline encounters specific patterns of input data or request structures, it fails to validate or properly manage these inputs, leading to resource consumption anomalies that can eventually result in system crashes or complete service disruption. This flaw operates at the core networking and data processing layer, making it particularly dangerous as it can affect applications across multiple domains including web servers, API endpoints, and distributed systems that rely on the pipeline for efficient data handling.
From an operational impact perspective, this vulnerability presents significant risks to system availability and business continuity, especially in high-traffic environments where ASP.NET Core applications process numerous concurrent requests. Attackers can exploit this weakness by sending carefully crafted requests that cause the pipeline to consume excessive memory or processing cycles, ultimately leading to denial of service conditions that affect legitimate users. The vulnerability is particularly dangerous because it can be triggered through normal application usage patterns, making it difficult to distinguish between legitimate traffic and malicious exploitation attempts. Organizations relying on affected versions of .NET Core 2.1 and ASP.NET Core 2.1 face potential service interruptions that could result in financial losses, reputation damage, and compliance violations.
The mitigation strategies for CVE-2018-8409 primarily involve immediate patching of affected systems through Microsoft's security updates, which address the underlying implementation issues in System.IO.Pipelines. Organizations should prioritize updating to the latest available versions of .NET Core 2.1 and ASP.NET Core 2.1 that contain the security fixes. Additionally, implementing proper input validation and request filtering mechanisms can help reduce the attack surface, though these measures serve as temporary workarounds rather than complete solutions. Network-level protections such as rate limiting and request monitoring can provide additional defense-in-depth measures, while regular security assessments should be conducted to identify potential exploitation vectors. This vulnerability aligns with CWE-400, which covers "Uncontrolled Resource Consumption" and relates to ATT&CK technique T1499.004 for "Endpoint Denial of Service" within the context of system resource exhaustion attacks. Organizations should also consider implementing automated monitoring solutions that can detect anomalous pipeline behavior and trigger incident response protocols when unusual resource consumption patterns are observed.