Headline

GHSA-h857-2g56-468g: @mattkrick/sanitize-svg vulnerable to Cross-Site Scripting (XSS)

Impact

The sanitize-svg package uses a deny-list-pattern to sanitize SVGs to prevent cross-site scripting (XSS). In doing so, literal <script>-tags and on-event handlers were detected:

[...]
  const svgEl = div.firstElementChild!
  const attributes = Array.from(svgEl.attributes).map(({ name }) => name)
  const hasScriptAttr = !!attributes.find((attr) => attr.startsWith('on'))
  const scripts = svgEl.getElementsByTagName('script')
  return scripts.length === 0 && !hasScriptAttr ? svg : null
[...]

There are more ways to embed JavaScript in XML files.

Anchor Tag (requires user to click link):

<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
  <a href="javascript:alert(document.domain)">
    <text x="50" y="50" text-anchor="middle">Lauritz</text>
  </a>
</svg>

Foreign Object Tag (no user interaction required):

<svg width="500" height="500" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
        <text x="20" y="35">Lauritz</text>
        <foreignObject width="500" height="500">
                <iframe xmlns="http://www.w3.org/1999/xhtml" src="javascript:confirm(document.domain);" width="400" height="250"/>
        </foreignObject>
</svg>

As a result, downstream software that relies on sanitize-svg and expects resulting SVGs to be safe, may be vulnerable to XSS. We are aware of at least one downstream project for which this vulnerability had security implications.

Patches

This vulnerability was addressed in v0.4.0.

Workarounds

N/A

2 years ago

ghsa

Open in Source

#xss #vulnerability #nodejs #git #java

GitHub Advisory Database
GitHub Reviewed
CVE-2023-22461

@mattkrick/sanitize-svg vulnerable to Cross-Site Scripting (XSS)

High severity GitHub Reviewed Published Jan 5, 2023 in mattkrick/sanitize-svg • Updated Jan 5, 2023

Package

npm @mattkrick/sanitize-svg (npm)

Affected versions

<= 0.3.1

Impact

The sanitize-svg package uses a deny-list-pattern to sanitize SVGs to prevent cross-site scripting (XSS). In doing so, literal <script>-tags and on-event handlers were detected:

[…] const svgEl = div.firstElementChild! const attributes = Array.from(svgEl.attributes).map(({ name }) => name) const hasScriptAttr = !!attributes.find((attr) => attr.startsWith(‘on’)) const scripts = svgEl.getElementsByTagName(‘script’) return scripts.length === 0 && !hasScriptAttr ? svg : null […]

There are more ways to embed JavaScript in XML files.

Anchor Tag (requires user to click link):

Foreign Object Tag (no user interaction required):

As a result, downstream software that relies on sanitize-svg and expects resulting SVGs to be safe, may be vulnerable to XSS. We are aware of at least one downstream project for which this vulnerability had security implications.

Patches

This vulnerability was addressed in v0.4.0.

Workarounds

N/A

References

GHSA-h857-2g56-468g
https://nvd.nist.gov/vuln/detail/CVE-2023-22461
mattkrick/sanitize-svg@b107e45

The `sanitize-svg` package, a small SVG sanitizer to prevent cross-site scripting attacks, uses a deny-list-pattern to sanitize SVGs to prevent XSS. In doing so, literal `<script>`-tags and on-event handlers were detected in versions prior to 0.4.0. As a result, downstream software that relies on `sanitize-svg` and expects resulting SVGs to be safe, may be vulnerable to cross-site scripting. This vulnerability was addressed in v0.4.0. There are no known workarounds

2 years ago

CVE

Open in Source

#xss #vulnerability #nodejs #java