Is CVE-2020-16171 being actively exploited?

CVE-2020-16171 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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

CVE-2020-16171 has a CVSS 3.1 base score of 6.5 (MEDIUM).

CVE-2020-16171

MEDIUM · CVSS 6.5EPSS 5.5%EU EUVD

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.

Key facts

CVSS score: 6.5 (v3.1)
Severity: MEDIUM
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Weakness (CWE): CWE-918
EPSS score: 5.5% (93th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2020-8137)
Published: September 21, 2020
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2020-8137 in the EU Vulnerability Database. Last updated in EUVD on August 4, 2024.

View on the EU Vulnerability Database

Affected products

acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup
acronis / cyber backup

Certified products that may be affected

2 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

Acronis Cyber Backup 12.5 SCS Hardened Edition Server v12.5 - Acronis SCS - Common Criteria CCEVS-VR-VID-11071-2020 - archived
Acronis Cyber Backup 12.5 SCS Hardened Edition Agent v12.5 - Acronis SCS - Common Criteria CCEVS-VR-VID-11072-2020 - archived

References

http://seclists.org/fulldisclosure/2020/Sep/33(Exploit, 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)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

Query CVEs from your AI assistant

The CVE/NVD Explorer brain answers CVE questions directly inside Claude, ChatGPT, or any MCP assistant — always up to date, no setup. Add it once and stop pasting advisories into chat.

Add the CVE brain