CVE-2021-43037: Kaseya Unitrends Backup

High severity, CVSS 7.8. EPSS: 0.5% chance of exploitation in the next 30 days.

An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. The Unitrends Windows agent was vulnerable to DLL injection and binary planting due to insecure default permissions. This allowed privilege escalation from an unprivileged user to SYSTEM.

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.