CVE-2020-17036 in Windows
Summary
by MITRE • 11/11/2020
Windows Function Discovery SSDP Provider Information Disclosure Vulnerability
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Analysis
by VulDB Data Team • 12/05/2020
The Windows Function Discovery SSDP Provider Information Disclosure Vulnerability represents a critical security flaw in Microsoft Windows operating systems that allows unauthorized information disclosure through the Simple Service Discovery Protocol implementation. This vulnerability specifically affects the SSDP (Simple Service Discovery Protocol) provider component within the Windows Function Discovery service, which is responsible for discovering network services and devices on local networks. The flaw exists in how the system handles certain SSDP packets and responses, potentially exposing sensitive information about network services and device configurations to unauthorized parties. According to CWE-200, this vulnerability falls under information disclosure categories where sensitive data is exposed to entities that should not have access to it, making it particularly concerning for enterprise environments where network visibility and service discovery are critical components of infrastructure management.
The technical implementation of this vulnerability stems from improper handling of SSDP messages within the Windows Function Discovery service. When the system processes incoming SSDP packets or responds to discovery requests, it fails to properly validate or sanitize the information contained within these messages before exposing them to network consumers. This allows attackers to potentially craft malicious SSDP requests that could trigger the disclosure of internal network service information, device identifiers, or other sensitive metadata that should remain confidential within the network ecosystem. The vulnerability is particularly dangerous because SSDP is designed to be a broadcast-based protocol that operates at the network layer, making it difficult to control or monitor precisely. Attackers could leverage this weakness to perform reconnaissance activities, mapping network services and identifying potential attack vectors without requiring elevated privileges or direct system access. The ATT&CK framework categorizes this as a reconnaissance technique under the T1046 sub-technique for network service scanning, where adversaries gather information about network services and devices to plan further attacks.
The operational impact of CVE-2020-17036 extends beyond simple information disclosure, as it can enable more sophisticated attack scenarios including service enumeration, network mapping, and potential privilege escalation opportunities. Organizations with multiple Windows systems running the vulnerable Function Discovery service may find their network infrastructure exposed to unauthorized discovery activities, potentially revealing service endpoints, device types, and operational configurations that could be leveraged in subsequent attacks. The vulnerability affects various Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, making it a widespread concern across enterprise environments. Network administrators may observe unusual SSDP traffic patterns or discover unauthorized service discovery activities that could indicate exploitation attempts. The information disclosure could potentially expose details about running services, device capabilities, or network topology that would otherwise remain hidden, creating opportunities for attackers to tailor more targeted attacks against specific services or system configurations.
Mitigation strategies for this vulnerability should focus on both immediate patching and network-level controls to prevent exploitation. Microsoft released security updates through the normal patching cycle that address the underlying SSDP handling flaws in the Function Discovery service implementation. Organizations should prioritize applying the relevant security updates as soon as possible, particularly in environments where network visibility and service discovery are critical components of the infrastructure. Network segmentation and firewall rules can help limit the exposure of SSDP traffic to only authorized systems and prevent unauthorized discovery activities from propagating throughout the network. Implementing network monitoring solutions that can detect unusual SSDP traffic patterns or unauthorized service discovery requests can provide early warning of potential exploitation attempts. Additionally, disabling unnecessary Function Discovery services or restricting their network access through group policy settings can reduce the attack surface. The vulnerability highlights the importance of proper input validation and sanitization in network protocol implementations, as outlined in CWE-20 and the broader principles of secure coding practices that prevent information leakage through protocol handling mechanisms.