CVE intelligence and bounded remediation

CVE-2020-12670 — Webmin Webmin security vulnerability

Medium CVSS 6.1

XSS exists in Webmin 1.941 and earlier affecting the Save function of the Read User Email Module / mailboxes Endpoint when attempting to save HTML emails. This module parses any output without sanitizing SCRIPT elements, as opposed to the View function, which sanitizes the input correctly. A malicious user can send any JavaScript payload into the message body and execute it if the user decides to save that email.

Severity
Medium
CVSS
6.1 (3.1)
Published
2020-10-12
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-79

Affected products

  • webmin / webmin

Matched remediation archetype

Cross-site scripting and unsafe browser output

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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