CVE-2020-16171

Name: CVE-2020-16171
Creator: NVD / NIST
Published: 2020-09-21T14:15:13.37+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 5.50%

Last modified Jun 17, 2026

CVE-2020-16171 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 5.50% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS Probability

5.50%

91.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-918

Affected Software

Vendor	Product	Versions
Acronis	Cyber Backup	<= 12.5
Acronis	Cyber Backup	12.5

References

http://seclists.org/fulldisclosure/2020/Sep/33Exploit, Mailing List, Third Party Advisory
https://www.rcesecurity.com/2020/09/CVE-2020-16171-Exploiting-Acronis-Cyber-Backup-for-Fun-and-Emails/Third Party Advisory
http://seclists.org/fulldisclosure/2020/Sep/33Exploit, Mailing List, Third Party Advisory
https://www.rcesecurity.com/2020/09/CVE-2020-16171-Exploiting-Acronis-Cyber-Backup-for-Fun-and-Emails/Third Party Advisory

Timeline

Published: Sep 21, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-16171?

How severe is CVE-2020-16171?

CVE-2020-16171 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 5.50% probability of exploitation in the next 30 days.

How do I fix CVE-2020-16171?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-16171?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST