CVE-2013-7454 — validator
MEDIUMCVE-2013-7454 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in validator. A fix is available for validator — see the affected versions and patch details below.
Multiple XSS Filter Bypasses in validator
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
validatornpmDescription
Versions of validator prior to 1.1.0 are affected by several cross-site scripting vulnerabilities due to bypasses discovered in the blacklist-based filter.
Proof of Concept
Various inputs that could bypass the filter were discovered:
Improper parsing of nested tags:
<s <onmouseover="alert(1)"> <;s onmouseover="alert(1)">This is a test</s>
Incomplete filtering of javascript: URIs:
<a href="javascriptJ a V a S c R iPt::alert(1)" "<s>">test</a>
UI Redressing:
<div style="z-index: 9999999; background-color: green; width: 100%; height: 100%">
<h1>You have won</h1>Please click the link and enter your login details:
<a href="http://example.com/">http://good.com</a>
</div>
Bypass via Nested Forbidden Strings:
<scrRedirecRedirect 302t 302ipt type="text/javascript">prompt(1);</scrRedirecRedirect 302t 302ipt>
Additional bypasses were discovered by Krzysztof Kotowicz in 2012 when auditing CodeIgniter's XSS filtering function, which this code was based off of.
Recommendation
If you are a developer currently using the xss filter function from the validator package, you should consider replacing it with the escape filter function from the same package. This function replaces all instances of angle brackets (<, >), ampersands, and quotation marks, so no HTML tags will be processed.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | validator | all versions | 1.1.0npm install validator@1.1.0 |
Affected Products
node.jsnodejsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for validator, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update validator to 1.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2013-7454 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2013-7454 in your dependencies?
Find it across npm, including transitive dependencies.