CVE-2025-48959 is a local privilege escalation vulnerability identified in the Acronis Cyber Protect Cloud Agent for Windows, specifically affecting versions prior to build 40077. The root cause is insecure file permissions (classified under CWE-276), which allow a user with limited privileges on the system to manipulate or replace files that the agent relies on, thereby escalating their privileges to a higher level. This vulnerability requires the attacker to have local access to the system and some level of user interaction, such as executing a malicious file or script. The CVSS v3.0 base score is 6.7, reflecting a medium severity level, with attack vector local (AV:L), attack complexity high (AC:H), privileges required low (PR:L), user interaction required (UI:R), and impacts on confidentiality, integrity, and availability all rated high (C:H/I:H/A:H). The vulnerability could allow unauthorized users to gain administrative or SYSTEM-level privileges, compromising the security posture of the affected system and potentially enabling further lateral movement or persistence. No public exploits or active exploitation in the wild have been reported to date. The vulnerability affects the Windows version of the Acronis Cyber Protect Cloud Agent, a widely used endpoint protection and backup solution in enterprise environments. The lack of a patch link indicates that remediation may require updating to a fixed build or applying vendor guidance once available.

The vulnerability poses a significant risk to organizations relying on Acronis Cyber Protect Cloud Agent on Windows endpoints. Successful exploitation can lead to unauthorized privilege escalation, allowing attackers to execute arbitrary code with elevated rights, potentially compromising sensitive data, altering system configurations, or disrupting backup and protection services. This can undermine the integrity and availability of critical systems and data, leading to operational downtime and increased risk of further attacks such as ransomware or data exfiltration. Since the agent is deployed in cloud protection and backup environments, the impact extends to cloud security posture and business continuity. Organizations with large Windows endpoint deployments using this agent are particularly vulnerable, especially if local user accounts are shared or if attackers gain initial footholds through phishing or insider threats. The medium CVSS score reflects the need for timely mitigation but also acknowledges the higher complexity and required user interaction for exploitation.

Organizations should immediately verify the version of Acronis Cyber Protect Cloud Agent deployed on their Windows endpoints and plan to upgrade to build 40077 or later once available. Until a patch is applied, administrators should audit and tighten file system permissions related to the agent’s installation directories and configuration files to prevent unauthorized modification. Implement strict local user account controls and limit the number of users with local access to critical systems. Employ endpoint detection and response (EDR) tools to monitor for suspicious activities indicative of privilege escalation attempts. Additionally, enforce the principle of least privilege and use application whitelisting to reduce the risk of malicious code execution. Regularly review and update security policies regarding local user interactions and educate users about the risks of executing untrusted files. Coordinate with Acronis support for any interim mitigation guidance and monitor for official patches or advisories.