What is CVE-2021-1571?

CVE-2021-1571 is a high-severity vulnerability in Cisco Small Business 220 Series Smart Plus Switches, classified under Improper Authentication. CVSS score: 7.2/10. Published 2021-06-16.

How severe is CVE-2021-1571?

High severity. CVSS v3 base score is 7.2 out of 10.

XSS in Cisco Small Business 220 Series Smart Plus Switches

CVE-2021-1571

Multiple vulnerabilities in the web-based management interface of Cisco Small Business 220 Series Smart Switches could allow an attacker to do the following: Hijack a user session Execute arbitrary commands as a root user on the underlying operating system Conduct a cross-site scripting (XSS) attack Conduct an HTML injection attack For more information about these vulnerabilities, see the Details section of this advisory.

Vulnerability class: Broken Authentication

Published 2021-06-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.097 (95.4th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 95th percentile — 95.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.097 · newest: 0.097 · change: 0.000

Affected products

Weakness classification (CWE)

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ciscosb-… (vendor-advisory, Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-1571?: CVE-2021-1571 is a high-severity vulnerability in Cisco Small Business 220 Series Smart Plus Switches, classified under Improper Authentication. CVSS score: 7.2/10. Published 2021-06-16.
How severe is CVE-2021-1571?: High severity. CVSS v3 base score is 7.2 out of 10.