SVG File Upload XSS

Medium Severity Technical Guide

Vulnerability Description

Allowing users to upload SVG files allows them to embed inline <script> tags inside the image file. When viewed directly in the browser, the scripts execute under your domain context.

Remediation Guide

To resolve this vulnerability, follow these config changes or developer practices:

Sanitize uploaded SVG files to strip scripts and event handlers, serve user-uploaded files from a separate sandbox domain, or enforce Content-Disposition: attachment.

Verify Your Fix

After applying the remediation, run an external attack-surface scan to verify that the vulnerability is no longer detected by WebScanify.

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