CVE-2021-29087: Synology Diskstation Manager

High severity, CVSS 7.5. EPSS: 1.4% chance of exploitation in the next 30 days.

Improper limitation of a pathname to a restricted directory ('Path Traversal') vulnerability in webapi component in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows remote attackers to write arbitrary files via unspecified vectors.

Affected products

• Synology Diskstation Manager: from 6.2, before 6.2.3-25426-3 (fixed in 6.2.3-25426-3)
• Synology Diskstation Manager Unified Controller: before 3.1-23033 (fixed in 3.1-23033)

Published 2021-06-23. Last modified 2026-06-17.