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MEDIUM

CVE-2020-16171

CVSS v3

6.5

MEDIUM

EPSS Score

5.5 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2020-16171 yet.

Full record on NVD

Description

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.

Technical details

Published
2020-09-21
Exploit-DB
EDB-49113

Frequently asked questions

What is CVE-2020-16171?

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.

Is CVE-2020-16171 actively exploited?

Active exploitation of CVE-2020-16171 has not been confirmed. Its EPSS score was 5.5% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-16171?

CVE-2020-16171 has a CVSS v3 base score of 6.5 (MEDIUM severity).

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