streamaserver/streama

XSS in the Upload Poster feature using an SVG image

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#1,088 opened on Sep 13, 2021

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BugHelp wanted

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Description

If uploading a SVG file in the poster file browser containing a script tag, this script tag will be executed when opening the file. example file:

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">

<svg version="1.1" baseProfile="full" xmlns="http://www.w3.org/2000/svg" id="mysvg">
<script>
alert(document.cookie);
</script>
</svg>

Contributor guide

Research direction
Examine the poster upload handler to see if SVG files are sanitized or if they are served with proper Content Type. Implement sanitization to remove script tags or convert SVG to a safe format.
Tech stack
javascript
Domain
securityfrontend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Web security basicsSVG format understanding
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65