CVE-2025-55677 is a vulnerability classified under CWE-822 (Untrusted Pointer Dereference) affecting the Windows Device Association Broker service in Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). The flaw arises when the service improperly dereferences pointers that can be influenced by an authorized local attacker, leading to memory corruption or unexpected behavior. This can be exploited to escalate privileges from a limited user context to SYSTEM or equivalent, granting full administrative control over the affected machine. The vulnerability does not require user interaction, but does require the attacker to have some level of local access (authenticated local user). The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity and low privileges required. No public exploits or patches are currently available, but the vulnerability is publicly disclosed and should be considered a significant risk. The Device Association Broker service is responsible for managing device pairing and association, making it a critical component in Windows 11's device management framework. Exploiting this vulnerability could allow attackers to bypass security controls, install persistent malware, or disrupt system operations.

For European organizations, this vulnerability poses a significant risk to endpoint security, particularly for enterprises and government agencies relying on Windows 11 25H2. Successful exploitation could lead to unauthorized privilege escalation, enabling attackers to execute arbitrary code with SYSTEM privileges, access sensitive data, and disrupt critical services. This could result in data breaches, ransomware deployment, or sabotage of IT infrastructure. The impact is especially severe for sectors with strict regulatory requirements such as finance, healthcare, and critical infrastructure operators. Given the local attack vector, insider threats or compromised user accounts could be leveraged to exploit this flaw. The absence of known exploits currently provides a window for proactive mitigation, but the high severity score indicates that exploitation could have widespread consequences across European organizations using affected Windows versions.

1. Monitor Microsoft security advisories closely and apply official patches immediately once released to remediate the vulnerability. 2. Restrict local user privileges by enforcing the principle of least privilege and limiting administrative rights to reduce the attack surface. 3. Employ endpoint detection and response (EDR) solutions to monitor for anomalous behavior related to the Device Association Broker service and privilege escalation attempts. 4. Harden device management policies to control which users and processes can interact with device association services. 5. Conduct regular audits of local user accounts and remove or disable unnecessary accounts to minimize potential attackers. 6. Implement application whitelisting and code integrity policies to prevent unauthorized code execution even if privilege escalation occurs. 7. Educate IT staff and users about the risks of local privilege escalation vulnerabilities and encourage reporting of suspicious activity. 8. Use network segmentation to isolate critical systems and reduce lateral movement opportunities post-exploitation.