CVE intelligence and bounded remediation

CVE-2019-18893 — Avast Secure Browser security vulnerability

Medium CVSS 6.1

XSS in the Video Downloader component before 1.5 of Avast Secure Browser 77.1.1831.91 and AVG Secure Browser 77.0.1790.77 allows websites to execute their code in the context of this component. While Video Downloader is technically a browser extension, it is granted a very wide set of privileges and can for example access cookies and browsing history, spy on the user while they are surfing the web, and alter their surfing experience in almost arbitrary ways.

Severity
Medium
CVSS
6.1 (3.1)
Published
2020-01-13
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-79

Affected products

  • avast / secure_browser / 77.1.1831.91
  • avg / secure_browser / 77.0.1790.77
  • video_downloader_project / video_downloader

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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