Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Checkout DevGuardView on GitHub
Search

GHSA-h857-2g56-468g

HighCVSS 7.6 / 10
Published Jan 5, 2023·Last modified Nov 8, 2023
Affected Components(0)

No affected components available

Description

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

Risk Scores
Base Score
7.6

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. The attacker needs the user to perform some action, like clicking a link. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information. There is a low impact on the integrity of the data.

Threat Intelligence
7.0

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
0.57%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Browse More

High severity
Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard