CVE-2025-59510 in Windows
Summary
by MITRE • 11/11/2025
Improper link resolution before file access ('link following') in Windows Routing and Remote Access Service (RRAS) allows an authorized attacker to deny service locally.
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Analysis
by VulDB Data Team • 01/05/2026
The vulnerability identified as CVE-2025-59510 represents a critical flaw in the Windows Routing and Remote Access Service that stems from improper link resolution before file access operations. This issue specifically affects the RRAS component responsible for managing network routing and remote access functionalities within Windows Server environments. The vulnerability exists in how the system handles symbolic links and file access operations, creating a potential pathway for malicious actors to exploit the service's file handling mechanisms. Attackers can leverage this weakness to manipulate file access behavior through carefully crafted symbolic link references, potentially leading to unauthorized access or service disruption. The flaw is particularly concerning because it operates at the kernel level within the RRAS service, making it difficult to detect and mitigate without proper system hardening measures. This type of vulnerability falls under the broader category of improper link resolution issues that are commonly classified as CWE-37, which specifically addresses improper resolution of symbolic links. The attack vector requires local access to the system, meaning an authorized user with appropriate privileges can exploit this weakness, though the impact extends beyond simple privilege escalation to include service availability and system stability. The vulnerability demonstrates a fundamental flaw in how the Windows operating system processes file access requests when symbolic links are involved, particularly in network service contexts where multiple file operations may occur simultaneously. This weakness can be exploited to create denial of service conditions by manipulating the file resolution process, potentially causing the RRAS service to fail or become unresponsive. The issue is particularly dangerous in enterprise environments where RRAS services are commonly deployed to manage network routing and remote access connectivity, as it could lead to widespread service disruption. From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1499.004 which covers network denial of service attacks, and T1068 which addresses local privilege escalation through service manipulation. The flaw demonstrates how seemingly minor issues in file access handling can create significant security implications when they occur within critical system services. The vulnerability's impact is amplified by the fact that RRAS services are often running with elevated privileges, making successful exploitation potentially more damaging than typical file access vulnerabilities. Security researchers have identified that this weakness allows for predictable manipulation of file access paths through symbolic link resolution, creating opportunities for both denial of service and potential information disclosure attacks. The Windows security model's handling of link resolution in service contexts has been found to be insufficiently robust, particularly when dealing with complex file access scenarios involving multiple symbolic link traversals. This vulnerability underscores the importance of proper input validation and file access control mechanisms in network services, as it shows how improper handling of symbolic links can create security boundaries that are easily circumvented. Organizations should consider this vulnerability as part of a broader security posture assessment, particularly in environments where remote access and routing services are heavily utilized. The exploitability of this vulnerability is enhanced by the fact that it does not require special privileges beyond those normally granted to authorized users within the system, making it accessible to a wider range of potential attackers. The technical implementation of the RRAS service fails to properly validate symbolic link targets before executing file operations, allowing for path traversal and access manipulation that can lead to service disruption or unauthorized access. This type of vulnerability is particularly challenging to detect through standard security scanning tools because it requires specific conditions related to symbolic link usage and file access patterns within the service context. The vulnerability's characteristics align with the broader category of path traversal issues that are commonly exploited in service-based applications, highlighting the need for comprehensive security testing of file access operations in network services. Organizations implementing security controls should prioritize patching this vulnerability as part of their regular update cycles, especially in environments where RRAS services are actively used for network connectivity management. The fix for this vulnerability typically involves implementing proper symbolic link validation and ensuring that all file access operations within the RRAS service properly resolve links before executing access requests. This remediation approach addresses the root cause of the vulnerability by strengthening the link resolution process and preventing unauthorized manipulation of file access paths. The vulnerability's presence in the RRAS service also highlights the need for continuous monitoring and auditing of service configurations, particularly those involving network access and routing functionality. Security professionals should consider implementing additional controls such as file access logging and monitoring to detect potential exploitation attempts before they can cause significant service disruption. The overall impact of this vulnerability extends beyond immediate service availability concerns to include potential data integrity and system stability issues that could affect network connectivity for multiple users.