Description

A high-risk vulnerability has been identified in the Windows Remote Access Connection Manager (RasMan) service that allows local attackers to escalate privileges and execute arbitrary code with SYSTEM-level access. The flaw is associated with CVE-2025-59230, a privilege escalation issue initially patched by Microsoft. However, security researchers later demonstrated that the original fix could be bypassed when combined with an additional unpatched logic flaw in the same service. This chained exploitation technique significantly increases the risk, as it enables attackers with basic local access to fully compromise affected Windows systems. The vulnerability impacts multiple Windows desktop and server versions and poses a serious threat in enterprise environments where local access may already be present through phishing, malware, or insider activity. The vulnerability exists in how the Windows Remote Access Connection Manager handles service trust relationships and RPC endpoint registration. RasMan is a privileged Windows service responsible for managing dial-up, VPN, and remote access connections. During normal operation, it registers specific RPC endpoints that other high-privilege Windows services trust and interact with. Researchers discovered that RasMan contains insufficient validation and flawed error handling logic that can be abused by a low-privileged local user. In the demonstrated attack chain, an attacker first triggers a controlled crash of the RasMan service using an unpatched flaw related to improper linked-list handling. When RasMan stops unexpectedly, its trusted RPC endpoint becomes unregistered. At this point, a malicious process running under the attacker’s control can register the same RPC endpoint before the legitimate service restarts. Because other SYSTEM-level services implicitly trust this endpoint, they connect to the attacker-controlled process and execute attacker-supplied code. This results in full SYSTEM-level code execution without requiring administrative privileges. While Microsoft addressed the primary elevation of privilege issue, the auxiliary service crash vector remains exploitable, allowing attackers to bypass protections. This makes the vulnerability particularly dangerous, as it can be reliably chained with other local access techniques to gain complete control over affected Windows machines.