CVE-2024-38168: Microsoft .NET Denial of Service Vulnerability

CVE-2024-38168 Overview

CVE-2024-38168 is a denial of service vulnerability affecting Microsoft .NET and Microsoft Visual Studio 2022. Microsoft disclosed the issue on August 13, 2024 as part of its scheduled security update cycle. The flaw is categorized under [CWE-400] Uncontrolled Resource Consumption and allows a remote, unauthenticated attacker to disrupt service availability by sending crafted network traffic to a vulnerable component.

Critical Impact

A remote attacker without authentication or user interaction can exhaust application resources and force .NET or Visual Studio 2022 processes into an unavailable state, breaking availability for downstream services.

Affected Products

• Microsoft .NET
• Microsoft Visual Studio 2022
• Applications built on affected .NET runtime versions

Discovery Timeline

• 2024-08-13 - Microsoft publishes security advisory for CVE-2024-38168
• 2024-08-13 - CVE-2024-38168 published to the National Vulnerability Database
• 2024-08-16 - Last updated in the NVD database

Technical Details for CVE-2024-38168

Vulnerability Analysis

The vulnerability resides in how .NET and Visual Studio 2022 process certain network-supplied input. An attacker can submit crafted requests that trigger uncontrolled resource consumption on the host. The mapped weakness, [CWE-400], indicates the affected component fails to constrain CPU, memory, or thread resources when handling adversary-controlled data. The result is availability loss for the application or service hosting the vulnerable runtime.

The vulnerability does not expose confidentiality or integrity, according to the CVSS impact metrics from NVD. Exploitation requires no privileges and no user interaction, and the attack proceeds across the network. Microsoft has not reported observed exploitation, and the issue is not listed in the CISA Known Exploited Vulnerabilities catalog. The EPSS probability is 2.913% at the 86.6 percentile, indicating elevated relative exploit likelihood compared to most CVEs.

Root Cause

The root cause is improper enforcement of resource limits when the .NET runtime parses or processes network input. When a malformed or oversized payload reaches the vulnerable code path, the component allocates work beyond safe bounds, eventually starving the process of CPU or memory.

Attack Vector

The attack vector is network-based. An attacker sends crafted requests to a service running an affected .NET runtime or to a Visual Studio 2022 component that processes remote input. No authentication, prior access, or user interaction is required. Refer to the Microsoft Security Update Guide for CVE-2024-38168 for the authoritative technical scope.

No public proof-of-concept code has been published for this CVE, and SentinelLabs does not produce synthetic exploit code. The exploitation mechanism follows the standard pattern for uncontrolled resource consumption flaws: repeated submission of crafted payloads causes the target process to consume resources until it stops responding.

Detection Methods for CVE-2024-38168

Indicators of Compromise

• Sudden spikes in CPU or memory utilization on hosts running .NET services with no corresponding legitimate workload increase
• Repeated, abnormally large or malformed inbound requests to .NET-based listeners from a small set of source addresses
• Crash dumps or process restarts associated with dotnet.exe, w3wp.exe, or other hosts of the .NET runtime

Detection Strategies

• Baseline normal resource consumption for .NET workloads and alert on sustained deviations correlated with external network activity
• Correlate inbound request volume and payload size anomalies with .NET process restarts captured in endpoint telemetry
• Apply behavioral identification of denial-of-service patterns through the Singularity Platform's behavioral AI engine, which flags anomalous process resource use across endpoints and workloads

Monitoring Recommendations

• Forward Windows Application and System event logs, IIS logs, and .NET runtime crash data into Singularity Data Lake for OCSF-normalized analysis
• Monitor public-facing endpoints exposing .NET services for repeated connections that precede availability degradation
• Track patch state of .NET runtimes and Visual Studio 2022 installations across managed assets to identify exposed hosts

How to Mitigate CVE-2024-38168

Immediate Actions Required

• Apply the Microsoft security updates released on August 13, 2024 for affected .NET versions and Visual Studio 2022
• Inventory all hosts running .NET and Visual Studio 2022 and prioritize internet-exposed services for patching
• Validate that automated update channels for .NET runtimes are functioning and have delivered the fix

Patch Information

Microsoft published vendor guidance and patches through the Microsoft Security Update Guide for CVE-2024-38168. Administrators should consult the advisory for the specific .NET and Visual Studio 2022 build numbers that resolve the issue and apply them through Windows Update, Microsoft Update Catalog, or the dotnet installer channels appropriate to their environment.

Workarounds

• Restrict network reachability of affected .NET services to trusted networks until patches are deployed
• Place rate limiting and request size caps at upstream load balancers or web application firewalls to reduce resource-exhaustion exposure
• Use process resource limits and automatic recycling for .NET worker processes to contain the impact of triggered conditions

# Example: list installed .NET runtimes to identify hosts that need patching
dotnet --list-runtimes
dotnet --list-sdks