Phishing by Navigating Browser Tabs

Summary

Acunetix 360 identified possible phishing by navigating browser tabs but was unable to confirm the vulnerability.

Open windows with normal hrefs with the tag target="_blank" can modify window.opener.location and replace the parent webpage with something else, even on a different origin.

Impact

While this vulnerability doesn't allow script execution, it does allow phishing attacks that silently replace the parent tab. If the links lack rel="noopener noreferrer" attribute, a third party site can change the URL of the source tab using window.opener.location.assign and trick the users into thinking that they’re still in a trusted page and lead them to enter their sensitive data on the malicious website.

Remediation

• Add rel=noopener to the links to prevent pages from abusing window.opener. This ensures that the page cannot access the window.opener property in Chrome and Opera browsers.
  
  
• For older browsers and in Firefox, you can add rel=noreferrer which additionally disables the Referer header.

<a href="..." target="_blank" rel="noopener noreferrer">...</a>

Severity

Classification