CVE-2025-9869: Razer Synapse 3 Privilege Escalation Flaw

CVE-2025-9869 Overview

CVE-2025-9869 is a local privilege escalation vulnerability in the Razer Synapse 3 Macro Module. The flaw resides in the Razer Synapse Service, which improperly handles filesystem operations that follow symbolic links. A local attacker with the ability to run low-privileged code can abuse the service to delete arbitrary files on the target system. Successful exploitation allows the attacker to execute arbitrary code in the context of NT AUTHORITY\SYSTEM. The issue is tracked as ZDI-CAN-26374 and categorized under CWE-59 (Improper Link Resolution Before File Access).

Critical Impact
Local attackers can escalate from a low-privileged user to SYSTEM by abusing symbolic link handling in the Razer Synapse Service.

Affected Products

Razer Synapse 3 (Windows)
Razer Synapse Macro Module
Razer Synapse Service component

Discovery Timeline

2025-10-29 - CVE-2025-9869 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-9869

Vulnerability Analysis

The vulnerability affects the Razer Synapse Service, a Windows service that runs with SYSTEM privileges to support Synapse 3 Macro Module functionality. The service performs file operations on paths that a low-privileged user can influence. Because the service does not validate whether the target path is a symbolic link, an attacker can redirect operations to protected filesystem locations. The result is an arbitrary file delete primitive executed under SYSTEM context.

Arbitrary file delete primitives on Windows are a well-known stepping stone to full SYSTEM code execution. Public research has documented techniques that convert arbitrary delete into arbitrary write, typically by targeting Windows Installer rollback directories or component manifests. Once an attacker achieves arbitrary write as SYSTEM, code execution follows directly.

Root Cause

The root cause is improper link resolution before file access, classified as [CWE-59]. The Synapse Service opens or removes files at attacker-controllable paths without first verifying that the final target is not a symbolic link, junction, or hard link. This is a classic Time-of-Check to Time-of-Use pattern in privileged Windows services that touch user-writable directories.

Attack Vector

Exploitation requires local access and the ability to execute code as a standard user. The attacker plants a symbolic link or NTFS junction in a directory that the Razer Synapse Service later processes. When the service performs its file operation, it follows the link and acts on a file path chosen by the attacker. Network access, user interaction, and administrative credentials are not required.

No public proof-of-concept exploit was referenced in the advisory at the time of publication. Refer to the Zero Day Initiative Advisory ZDI-25-919 for additional technical detail.

Detection Methods for CVE-2025-9869

Indicators of Compromise

Creation of symbolic links, junctions, or reparse points in directories written to by the Razer Synapse Service, such as ProgramData\Razer subfolders.
File deletions in protected paths (for example, C:\Windows\System32 or C:\Program Files) occurring shortly after Razer Synapse Service activity.
Unexpected child processes spawned by Razer Synapse Service.exe running as SYSTEM.

Detection Strategies

Monitor process telemetry for standard-user processes invoking mklink, CreateSymbolicLink, or reparse-point APIs against Razer directories.
Alert on file deletions performed by the Razer Synapse Service where the target path resolves outside the expected Razer working directories.
Correlate low-privileged user activity with SYSTEM-context file operations occurring in the same directory tree within a short time window.

Monitoring Recommendations

Enable Windows object access auditing on ProgramData\Razer and related Razer directories to capture link creation and file deletion events.
Track integrity of files in System32 and privileged application directories with file integrity monitoring.
Review installations of Razer Synapse 3 across the fleet and inventory endpoints running vulnerable versions.

How to Mitigate CVE-2025-9869

Immediate Actions Required

Update Razer Synapse 3 to the latest version released by Razer that addresses CVE-2025-9869.
Restrict interactive logon on systems running Razer Synapse 3 to trusted users only.
Remove Razer Synapse 3 from servers, shared workstations, and other multi-user systems where it is not required.

Patch Information

Razer has not published a vendor advisory URL in the CVE record at the time of writing. Consult the Zero Day Initiative Advisory ZDI-25-919 and the Razer Synapse update channel for the fixed version. Apply the vendor-supplied patch as soon as it is available in your environment.

Workarounds

Disable or stop the Razer Synapse Service on endpoints that do not require macro or peripheral configuration functionality.
Uninstall Razer Synapse 3 from endpoints where Razer peripherals are not in use.
Apply application allowlisting to prevent low-privileged users from executing symbolic-link creation tooling in directories touched by the service.

bash

# Stop and disable the Razer Synapse Service as a temporary mitigation (run as Administrator)
sc.exe stop "Razer Synapse Service"
sc.exe config "Razer Synapse Service" start= disabled