CVE-2025-29808 is a medium-severity vulnerability affecting Microsoft Windows Server 2022 (build 10.0.20348.0). It involves the use of a cryptographic primitive within Windows Cryptographic Services that has a risky implementation, classified under CWE-1240. This weakness allows an authorized local attacker—someone with limited privileges on the affected system—to disclose sensitive information. The vulnerability does not require user interaction and has a low attack complexity, but it requires local access with some privileges (PR:L). The impact is primarily on confidentiality, as the attacker can extract information that should remain protected by cryptographic means, potentially exposing sensitive data or cryptographic keys. There is no indication of impact on integrity or availability. The vulnerability has not been observed exploited in the wild, and no patches or exploit code are currently publicly available. The CVSS v3.1 score is 5.5, reflecting a medium risk level due to the local attack vector and limited scope of impact. The issue stems from a cryptographic primitive implementation flaw, which could mean improper key management, weak randomness, or side-channel leakage, but exact technical details are not disclosed. This vulnerability highlights the importance of robust cryptographic implementations in server environments, especially those handling sensitive operations or data.

For European organizations, this vulnerability poses a risk primarily to confidentiality of sensitive information processed or stored on Windows Server 2022 systems. Organizations running critical infrastructure, financial services, healthcare, or government services on affected servers could face data leakage risks if attackers gain local access. Although exploitation requires local privileges, insider threats or attackers who have compromised lower-privileged accounts could leverage this flaw to escalate information disclosure. This could lead to exposure of cryptographic keys or sensitive configuration data, undermining trust in encrypted communications or stored secrets. The impact is less severe than remote code execution vulnerabilities but still significant for organizations with strict data protection requirements under GDPR and other regulations. The absence of known exploits reduces immediate risk, but the medium severity score warrants timely mitigation to prevent potential future attacks.

European organizations should prioritize the following mitigations: 1) Apply any available security updates from Microsoft as soon as they are released, even though no patches are currently listed, monitoring official Microsoft security advisories closely. 2) Restrict local access to Windows Server 2022 systems to trusted administrators only, using strict access controls and multi-factor authentication to reduce the risk of unauthorized local privilege use. 3) Implement robust endpoint detection and response (EDR) solutions to monitor for suspicious local activity that could indicate exploitation attempts. 4) Conduct regular audits of user privileges and remove unnecessary local accounts or rights that could be leveraged by attackers. 5) Employ network segmentation to limit lateral movement within the environment, reducing the chance that an attacker with local access on one server can reach others. 6) Consider additional cryptographic hardening and key management best practices to minimize the impact of any cryptographic primitive weaknesses. 7) Prepare incident response plans that include scenarios for local privilege information disclosure to ensure rapid containment if exploitation is detected.