This vulnerability involves improper limitation of a pathname to a restricted directory in Synology Hyper Backup's Backup.Repository webapi component. Remote authenticated administrators can exploit this path traversal flaw to write certain files with non-sensitive content. The exact exploitation vectors are unspecified. The vulnerability is present in versions prior to 4.1.2-4036. The CVSS 3.1 base score is 4.1, reflecting network attack vector, low attack complexity, high privileges required, no user interaction, scope changed, no confidentiality impact, limited integrity impact, and no availability impact.

The vulnerability allows remote authenticated users with administrator privileges to write specific files containing non-sensitive information, potentially impacting data integrity. There is no impact on confidentiality or availability. The scope of the vulnerability is limited to on-premises Synology Hyper Backup installations before version 4.1.2-4036. No known exploitation in the wild has been reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since the vulnerability affects versions before 4.1.2-4036, upgrading to version 4.1.2-4036 or later may address the issue if confirmed by Synology. Until official guidance or patches are available, restrict administrator access to trusted personnel only and monitor for unusual file writes related to the Backup.Repository webapi component.