Description
The web application produces links to untrusted external sites outside of its sphere of control, but it does not properly prevent the external site from modifying security-critical properties of the window.opener object, such as the location property.
When a user clicks a link to an external site (“target”), the target=”_blank” attribute causes the target site’s contents to be opened in a new window or tab, which runs in the same process as the original page. The window.opener object records information about the original page that offered the link. If an attacker can run script on the target page, then they could read or modify certain properties of the window.opener object, including the location property – even if the original and target site are not the same origin. An attacker can modify the location property to automatically redirect the user to a malicious site, e.g. as part of a phishing attack. Since this redirect happens in the original window/tab – which is not necessarily visible, since the browser is focusing the display on the new target page – the user might not notice any suspicious redirection.
Modes of Introduction:
– Architecture and Design
Likelihood of Exploit: Medium
Related Weaknesses
Consequences
Confidentiality: Alter Execution Logic
The user may be redirected to an untrusted page that contains undesired content or malicious script code.
Potential Mitigations
Phase: Architecture and Design
Description:
Specify in the design that any linked external document must not be granted access to the location object of the calling page.
Phase: Implementation
Description:
Phase: Implementation
Description: