CVE-2025-41757: Arbitrary File Write in UBR (ubr-restore)

The impact of this vulnerability is severe. An attacker can exploit it to gain arbitrary file write access, effectively bypassing file system permissions. This could lead to the creation of malicious executables, modification of critical system files, or the insertion of backdoors. Successful exploitation could result in complete system compromise, including privilege escalation to root or SYSTEM level. The ability to overwrite arbitrary files significantly expands the attack surface and allows for persistent access and control over the affected system. The lack of validation on the backup archive contents is the root cause, making it trivial for an attacker to craft a malicious archive.

1. Reserved2025-04-16
2. Published2026-03-09
3. EPSS updated2026-03-23

The primary mitigation is to immediately upgrade to version 6.0.1.0 or later, which addresses the vulnerability. If upgrading is not immediately feasible, consider implementing strict access controls on the backup restore functionality, limiting who can initiate restores. Network segmentation can also help to isolate the UBR (ubr-restore) service and limit the potential blast radius. Monitor system logs for unusual file creation or modification activity, particularly in sensitive system directories. Consider implementing a Web Application Firewall (WAF) to filter potentially malicious backup archive uploads, although this is not a complete solution.