CVE-2021-43040: Kaseya Unitrends Backup

High severity, CVSS 8.8. EPSS: 1.8% chance of exploitation in the next 30 days.

An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. The privileged vaultServer could be leveraged to create arbitrary writable files, leading to privilege escalation.

Affected products

• Kaseya Unitrends Backup: from 10.0, before 10.5.5 (fixed in 10.5.5)

Published 2021-12-06. Last modified 2026-06-17.