CVE-2024-38091 in Windows
Summary
by MITRE • 07/09/2024
Microsoft WS-Discovery Denial of Service Vulnerability
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Analysis
by VulDB Data Team • 05/25/2026
The Microsoft WS-Discovery Denial of Service vulnerability represents a critical weakness in the Web Services Dynamic Discovery protocol implementation within Windows operating systems. This vulnerability stems from improper input validation and handling of malformed WS-Discovery messages that can be transmitted over the network to target systems. The flaw exists in how the Windows service processes incoming discovery requests, particularly when handling specific packet structures that trigger unexpected behavior in the underlying discovery engine. According to CWE-400, this vulnerability falls under the category of uncontrolled resource consumption, where malicious actors can exploit the protocol implementation to exhaust system resources through carefully crafted network traffic.
The technical exploitation of this vulnerability occurs when an attacker sends malformed WS-Discovery packets to a target system that has the Windows Web Services stack enabled. The discovery protocol typically operates on UDP port 3702 and allows devices to discover services on a network automatically. When the target system receives these malformed packets, the WS-Discovery service fails to properly validate the incoming data structures, leading to resource exhaustion or service crashes. The vulnerability is particularly dangerous because it can be exploited remotely without authentication requirements, making it a prime candidate for automated attacks. This aligns with ATT&CK technique T1499.004 which covers network denial of service attacks targeting Windows services. The implementation flaw allows attackers to cause the Windows service hosting the discovery functionality to consume excessive CPU cycles or memory resources, ultimately resulting in system instability or complete service unavailability.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire network infrastructures where WS-Discovery is actively used. Organizations relying on automated service discovery mechanisms for network management, device configuration, or application deployment face significant risks when this vulnerability exists in their systems. The attack surface is particularly broad since WS-Discovery is enabled by default on many Windows versions and is commonly used in enterprise environments for service location and network automation. System administrators may experience cascading failures as the affected service becomes unresponsive, potentially blocking legitimate discovery requests and disrupting normal network operations. The vulnerability affects multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, making it a widespread concern across enterprise networks. According to Microsoft security advisories, successful exploitation can lead to complete denial of service conditions that require system restarts to resolve, causing significant downtime and operational disruption.
Mitigation strategies for this vulnerability involve multiple layers of defensive measures that address both immediate patching requirements and network-level protections. The primary recommendation is to apply the relevant Microsoft security updates that address the WS-Discovery implementation flaws, which typically include fixes to input validation routines and resource management within the discovery service. Network administrators should consider implementing firewall rules that restrict access to UDP port 3702 from untrusted networks, effectively blocking external discovery requests while maintaining internal functionality. The principle of least privilege should be applied by disabling WS-Discovery services on systems where automatic service discovery is not required, particularly on servers and workstations that do not need to participate in network discovery protocols. Additionally, monitoring network traffic for unusual patterns of WS-Discovery messages can help detect potential exploitation attempts, with security information and event management systems configured to alert on abnormal discovery traffic volumes. Organizations should also consider implementing network segmentation strategies to isolate critical systems from general network access, reducing the attack surface for this particular vulnerability. The ATT&CK framework suggests that network segmentation and access control measures provide effective defenses against this type of service denial attack, as they limit the potential impact of successful exploitation attempts.