CVE-2024-43484: Microsoft .NET Framework DoS Vulnerability

CVE-2024-43484 Overview

CVE-2024-43484 is a Denial of Service vulnerability affecting Microsoft .NET, .NET Framework, and Visual Studio. This vulnerability is classified under CWE-407 (Inefficient Algorithmic Complexity), indicating that the flaw involves processing operations that can be exploited to consume excessive computational resources, leading to service disruption.

The vulnerability allows remote attackers to cause a denial of service condition without requiring authentication or user interaction. Applications built on vulnerable versions of .NET and .NET Framework are susceptible to resource exhaustion attacks that can render services unavailable.

Critical Impact

Remote unauthenticated attackers can cause denial of service conditions affecting .NET, .NET Framework, and Visual Studio applications across Windows, macOS, and Linux platforms.

Affected Products

• Microsoft .NET Framework 2.0 SP2, 3.0 SP2, 3.5, 3.5.1, 4.6, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, and 4.8.1
• Microsoft .NET (cross-platform versions for Windows, macOS, and Linux)
• Microsoft Visual Studio 2022
• Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
• Microsoft Windows 11 (versions 21H2, 22H2, 23H2, 24H2)
• Microsoft Windows Server 2008, 2008 R2, 2012, 2012 R2, 2016, 2019, 2022, and 2022 23H2

Discovery Timeline

• October 8, 2024 - CVE-2024-43484 published to NVD
• March 28, 2025 - Last updated in NVD database

Technical Details for CVE-2024-43484

Vulnerability Analysis

This denial of service vulnerability stems from inefficient algorithmic complexity within .NET, .NET Framework, and Visual Studio components. The flaw can be exploited remotely over the network without requiring any privileges or user interaction. When triggered, the vulnerability causes excessive resource consumption that leads to service unavailability.

The attack surface is broad due to the widespread deployment of .NET Framework across enterprise environments and the cross-platform nature of modern .NET applications. Applications processing untrusted input may be particularly vulnerable if they trigger the affected code paths.

Root Cause

The vulnerability is rooted in CWE-407 (Inefficient Algorithmic Complexity). This weakness occurs when an algorithm's worst-case computational complexity is significantly higher than expected, allowing attackers to craft inputs that trigger expensive processing operations. In the context of .NET and .NET Framework, this can manifest during data parsing, serialization, or other input processing operations where malicious input causes disproportionate resource consumption.

Attack Vector

The attack can be executed remotely over the network. An attacker can send specially crafted requests or data to applications built on vulnerable .NET or .NET Framework versions. The malicious input triggers algorithmic complexity issues that consume excessive CPU, memory, or other system resources, ultimately causing the application to become unresponsive or crash.

Since no authentication or user interaction is required, internet-facing applications are at heightened risk. Web services, APIs, and other networked applications built on affected frameworks represent primary attack targets.

Detection Methods for CVE-2024-43484

Indicators of Compromise

• Unusual spikes in CPU or memory utilization on systems running .NET or .NET Framework applications
• Application timeouts or unresponsiveness coinciding with specific request patterns
• Repeated application pool recycling or service restarts in IIS environments
• Anomalous network traffic patterns targeting .NET-based services

Detection Strategies

• Deploy application performance monitoring to detect abnormal resource consumption in .NET applications
• Implement rate limiting and request throttling on exposed .NET services to mitigate potential DoS attempts
• Configure alerting for sustained high CPU or memory usage on application servers
• Review application logs for patterns indicating repeated processing of potentially malicious inputs

Monitoring Recommendations

• Enable detailed logging for .NET applications to capture request metadata and processing times
• Monitor Windows Event Logs for application crashes or .NET runtime exceptions
• Implement network-level monitoring to identify unusual traffic volumes targeting .NET services
• Establish baseline metrics for normal application behavior to facilitate anomaly detection

How to Mitigate CVE-2024-43484

Immediate Actions Required

• Apply Microsoft security updates released in October 2024 addressing CVE-2024-43484
• Prioritize patching internet-facing applications and services built on .NET or .NET Framework
• Review and update Visual Studio 2022 installations to patched versions
• Implement network-level protections such as rate limiting while patches are deployed

Patch Information

Microsoft has released security patches addressing this vulnerability. Organizations should consult the Microsoft Security Response Center advisory for specific update guidance. The patches are available through Windows Update, Microsoft Update Catalog, and Visual Studio update channels.

For NetApp customers, additional guidance is available in the NetApp Advisory NTAP-20250328-0007.

Workarounds

• Implement Web Application Firewalls (WAF) with rules to detect and block potential DoS attack patterns
• Configure request timeouts and resource limits for .NET applications to contain impact
• Isolate vulnerable applications behind reverse proxies with rate limiting capabilities
• Consider temporarily disabling non-essential .NET services until patches can be applied

# Example: Configure IIS request limits to mitigate DoS impact
# Set maximum content length and query string length
appcmd set config /section:requestLimits /maxAllowedContentLength:30000000
appcmd set config /section:requestLimits /maxQueryString:2048

# Configure request timeout in web.config
# <httpRuntime executionTimeout="30" />