XSS in Webmin

CVE-2020-8821

An Improper Data Validation Vulnerability exists in Webmin 1.941 and earlier affecting the Command Shell Endpoint. A user may enter HTML code into the Command field and submit it. Then, after visiting the Action Logs Menu and displaying logs, the HTML code will be rendered (however, JavaScript is not executed). Changes are kept across users.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.791 (99.6th percentile), scored .

High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.6% 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-2020-8821: fell from 0.802 to 0.791.

EPSS over last 30 days · oldest: 0.802 · newest: 0.791 · change: -0.012

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-8821?
CVE-2020-8821 is a medium-severity vulnerability in Webmin, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2020-10-12.
How severe is CVE-2020-8821?
Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2020-8821 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.