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Target="_blank" - the most underestimated vulnerability ever

by Alex Yumashev · Updated Aug 25 2021

People using target='_blank' links usually have no idea about this curious fact:

The linked page gains partial access to the linking page via the window.opener object.

The newly opened tab can then change the window.opener.location to some phishing page. Users trust the page that is already opened, they won't get suspicious.

Example attack scenario

How to fix

Add this to your outgoing links.


Update: FF does not support "noopener" so add this.

rel="noopener noreferrer"

Remember, that every time you open a new window via; you're also "vulnerable" to this, so always reset the "opener" property

var newWnd =;
newWnd.opener = null;

PS. Interestingly, Google doesn't seem to care.