CVE-2025-9870 is a local privilege escalation vulnerability identified in Razer Synapse 3, version 3.10.228.21112, specifically within its Philips HUE module installer component. The vulnerability arises from improper handling of symbolic links (CWE-59: Improper Link Resolution Before File Access), where the installer fails to correctly validate or resolve symbolic links before performing file operations. An attacker who already has the ability to execute code with low privileges on the affected system can create malicious symbolic links that cause the installer to delete arbitrary files. This file deletion can be leveraged to escalate privileges by overwriting or removing critical system files or configurations, ultimately allowing the attacker to execute arbitrary code with SYSTEM-level privileges. The vulnerability does not require user interaction and has a CVSS v3.0 score of 7.8, indicating high severity due to its impact on confidentiality, integrity, and availability. The flaw was reported by ZDI (ZDI-CAN-26375) and publicly disclosed on October 29, 2025. Although no exploits have been observed in the wild, the vulnerability poses a significant risk in environments where Razer Synapse 3 is installed, especially on systems where multiple users have local access or where attackers can gain low-level code execution through other means. The Philips HUE module installer’s failure to securely handle symbolic links is the root cause, making it possible to manipulate file operations to the attacker's advantage. This vulnerability highlights the risks associated with improper file system operations in privileged installers and the importance of secure link resolution to prevent local privilege escalation attacks.

For European organizations, the impact of CVE-2025-9870 can be substantial, particularly in environments where Razer Synapse 3 is deployed for managing gaming peripherals or Philips HUE integrations. Successful exploitation allows attackers to escalate privileges from a low-privileged user to SYSTEM, effectively gaining full control over the affected machine. This can lead to unauthorized access to sensitive data, disruption of critical services, and the potential for persistent malware installation. In corporate or enterprise environments, compromised systems could serve as footholds for lateral movement, increasing the risk of broader network compromise. The vulnerability’s ability to delete arbitrary files also threatens system stability and availability, potentially causing denial of service conditions. Given the high CVSS score and the nature of the vulnerability, organizations face risks to confidentiality, integrity, and availability. The threat is particularly relevant for organizations with shared or multi-user systems, development environments, or those that allow local code execution by untrusted users. The absence of known exploits in the wild reduces immediate risk but does not eliminate the urgency for mitigation, as the vulnerability could be weaponized by attackers targeting European entities with valuable intellectual property or critical infrastructure.

1. Restrict local user permissions to prevent untrusted users from executing arbitrary code or creating symbolic links in sensitive directories. 2. Implement strict file system monitoring to detect and alert on suspicious symbolic link creation or deletion activities, especially within directories used by Razer Synapse 3 and its Philips HUE module. 3. Apply the official patch from Razer as soon as it becomes available; monitor vendor advisories closely. 4. Use application whitelisting and endpoint protection solutions to limit unauthorized execution of installers or scripts that could exploit this vulnerability. 5. Conduct regular audits of installed software versions across endpoints to identify and remediate vulnerable Razer Synapse 3 installations. 6. Educate users about the risks of running untrusted code locally and enforce least privilege principles to minimize the attack surface. 7. Consider isolating or sandboxing systems that require Razer Synapse 3 to limit the blast radius of potential exploitation. 8. Employ robust backup and recovery procedures to mitigate the impact of arbitrary file deletions caused by exploitation attempts.