Fix code scanning alert - DOM text reinterpreted as HTML

[DonnieBLT]

Tracking issue for:

• https://github.com/OWASP/BLT/security/code-scanning/11

[JisanAR03]

hello, can you assign this issue to me please? i can work on it.

can you please tell me, how do you know what's the issue is?

[manthan-sharma-23]

@DonnieBLT Hey there Donnie can you please ellaborate a bit more on this so that i can try to fix the issue .THank you !

[JisanAR03]

/assign

[github-actions]

You are already assigned to another open issue, please wait until until it's closed or remove your assignment to get assigned to this issue.

[DonnieBLT]

The issue highlighted is a potential security vulnerability related to DOM-based cross-site scripting (XSS). DOM-based XSS arises when a script takes improperly sanitized data from the DOM and uses it in a way that might be executable. The specific issue here is with the text from a DOM node being interpreted as HTML without escaping meta-characters.

Here's a step-by-step guide on how to address this:

1. Understand the Problem:

   • Ensure that you know where the untrusted data is coming from. In the provided code, it appears that the untrusted data could be coming from the 'href' attribute or the 'data-target' attribute of a DOM element.

2. Escape Before Using in HTML Context:

   • Whenever you want to insert data into the DOM, it should be properly escaped to prevent any executable code from running.

3. Update the Code:

   • Before using the href or data-target attributes (or any other user-influenced attributes), they should be sanitized.
   • For example, if you're trying to prevent any <script> tags or other HTML from executing, you might use a function to escape these characters.

   function escapeHTML(str) {
       var div = document.createElement('div');
       div.appendChild(document.createTextNode(str));
       return div.innerHTML;
   }

   Then, whenever you grab a potentially unsafe attribute, pass it through this function:

   var href = escapeHTML($(this).attr('href'));

4. Avoid innerHTML for Inserting User Data:

   • Instead of using innerHTML, prefer safer alternatives like textContent or innerText. If you need to insert HTML, make sure it's sanitized using a trusted library.

5. Utilize Content Security Policy (CSP):

   • Implement a Content Security Policy on your website. A CSP can prevent a wide range of cross-site scripting attacks by restricting the sources of executable scripts.

6. Review Other Parts of Your Code:

   • It's important to check other parts of your application for similar issues. XSS vulnerabilities can be present in many different parts of an application.

7. Regularly Update Libraries:

   • If this vulnerability is in a third-party library (like Bootstrap in this case), ensure that you are using the latest version. Library maintainers often release patches for known vulnerabilities.

8. Testing:

   • After making these changes, test your application thoroughly to ensure that the vulnerability is fixed without introducing new issues.

Remember that security is a multi-layered approach. Even after fixing this issue, it's essential to maintain good security practices and regularly review and update your code and dependencies.