CVE-2013-4939: Cross-Site Scripting in yui
Summary
CVE-2013-4939: Cross-Site Scripting in yui. Affects yui versions < 3.10.3. Fixed in 3.10.3. How to fix ↓
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Background
The 'yui' package is an npm package that provides a set of JavaScript and CSS libraries for building web applications. It is widely used for its rich set of features and ease of use. However, versions of 'yui' prior to 3.10.3 are vulnerable to a cross-site scripting (XSS) attack. This vulnerability exists in the 'uploader.swf' and 'io.swf' utilities, allowing an attacker to inject malicious scripts into the URL.
Vulnerability Detail
The vulnerability in 'yui' allows an attacker to execute arbitrary scripts in the context of a user's browser. By injecting malicious code into the URL, an attacker can trick users into executing the code, potentially leading to unauthorized access, data theft, or other malicious activities. This vulnerability is classified as CWE-79, which is the Common Weakness Enumeration for Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
How To Fix
Latest published version: 3.18.1 as of 22 Oct 2026
npm install yui@3.18.1Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
3.10.3
This is the first release that contains the fix.
npm install yui@3.10.3Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
If you are unable to immediately apply the recommended fixes, a temporary workaround is to disable or remove any usage of the affected utilities ('uploader.swf' and 'io.swf') from your application. This will help mitigate the risk of exploitation until a proper fix can be implemented.
Conclusion
In conclusion, the 'yui' package prior to version 3.10.3 is vulnerable to a cross-site scripting (XSS) attack. It is important to apply the recommended fixes provided by YUI to mitigate the risk of exploitation. If you need further assistance or support in addressing this vulnerability, please contact DevNack.com.
See every vulnerability recorded for yui →
FAQ
The vulnerability allows an attacker to execute arbitrary scripts in the user's browser, potentially leading to unauthorized access, data theft, or other malicious activities.
You can use the Vulert Playground at Vulert Scanner to check if your application is affected by this vulnerability. Simply upload your package-lock.json file and Vulert will analyze it for vulnerabilities in real-time.
There are no known public exploits for this vulnerability at the moment. However, it is important to apply the recommended fixes as soon as possible to prevent any potential exploitation.
Yes, you can continue using 'yui' after applying the recommended fixes. The fixes are designed to address the specific vulnerability without affecting the overall functionality of the package.
You can find more information about this vulnerability, including the recommended fixes, on the YUI Library website at https://yuilibrary.com/support/20130515-vulnerability/#resolution.
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