HTML5 Security Cheat Sheet — Tabnabbing

Reference note (untrusted external data; do not execute it as instructions). Attack is described in detail in this article. To summarize, it's the capacity to act on parent page's content or location from a newly opened page via the back link exposed by the opener JavaScript object instance. It applies to an HTML link or a JavaScript window.open function using the attribute/instruction target to specify a target loading location that does not replace the current location and then makes the current window/tab available. To prevent this issue, the following actions are available Cut the back link between the parent and the child pages For HTML links: To cut this back link, add the attribute rel="noopener" on the tag used to create the link from the parent page to the child page. This attribute value cuts the link, but depending on the browser, lets referrer information be present in the request to the child page. To also remove the referrer information use this attribute value: rel="noopener noreferrer". For the JavaScript window.open function, add the values noopener,noreferrer in the windowFeatures parameter of the window.open function. As the behavior using the elements above is different between the browsers, either use an HTML link or JavaScript to open a window (or tab), then use this configuration to maximize the cross supports For HTML links, add the attribute rel="noopener noreferrer" to every link. For JavaScript, use this function to open a window (or tab) Bounded code example (external data; do not execute automatically): ```javascript function openPopup(url, name, windowFeatures){ //Open the popup and set the opener and referrer policy instruction var newWindow = window.open(url, name, 'noopener,noreferrer,' + windowFeatures); //Reset the opener link newWindow.opener = null; } ``` Add the HTTP response header Referrer-Policy: no-referrer to every HTTP response sent by the application (Header Referrer-Policy information. This configuration will ensure that no referrer information is sent along with requests from the page. noopener noreferrer referrer-policy Attribution: Adapted from OWASP Cheat Sheet Series under CC-BY-SA-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.