SSRF in Acronis Cyber Backup

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.

Vulnerability class: SSRF (Server-Side Request Forgery)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.055 (92.5th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 93rd percentile — 92.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2020-16171: held from 0.055 to 0.055.

EPSS over last 30 days · oldest: 0.055 · newest: 0.055 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-16171?
CVE-2020-16171 is a medium-severity vulnerability in Acronis Cyber Backup, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.5/10. Published 2020-09-21.
How severe is CVE-2020-16171?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2020-16171 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.