CVE-2020-16171: Acronis Cyber Backup

Medium severity, CVSS 6.5. EPSS: 5.5% chance of exploitation in the next 30 days.

An issue was discovered in Acronis Cyber Backup before 12.5 Build 16342. Some API endpoints on port 9877 under /api/ams/ accept an additional custom Shard header. The value of this header is afterwards used in a separate web request issued by the application itself. This can be abused to conduct SSRF attacks against otherwise unreachable Acronis services that are bound to localhost such as the NotificationService on 127.0.0.1:30572.

Affected products

• Acronis Cyber Backup: up to and including 12.5; version 12.5 only

Published 2020-09-21. Last modified 2026-06-17.