Description:

1. Hello @bookwyrm-social I found a tabnabbing vulnerability. attack is possible due to taget=_blank or Tab nabbing via window.opener.

VISIT:- https://bookwyrm.social/

SUMMARY:

1. I was browsing the site and found a tabnabbing vulnerability . As per the observation I found that attack is possible due to taget=_blank or Tab nabbing via window.opener. When you open a link in a new tab ( target="_blank" ), the page that opens in a new tab can access the initial tab and change it's location using the window.opener property.

STEPS TO REPRODUCE:

1. 1- Open the website URL :- https://bookwyrm.social/

2. 2- Right-click and click on inspect element

3. 3- Locate the cursor to Element Tab then do CTRL+F or Search for taget="_blank"

4. 4- If you get blank with a link it means website can be vulnerable like , open redirect like vulnerabilities

5. 5- For More Details To Check the POC

POC Screenshot 1:

POC Screenshot 2:

MITIGATIONS:-

In order to mitigate this issue, developers are encouraged to use rel="nofollow noopener noreferrer" as follows: <a target="_blank" class="btn external-url" href=#" https://evil.com " rel="nofollow noopener noreferrer"><i class="fa fa-external-link"></i> </a>

Don't open links in new tabs using the target="_blank" Add attribute rel="noreferrer" which also disables referrer Set the window.opener attribute to null on the new tab before redirecting, like this: <script>var w=window.open(url, "target=_blank");w.opener= null;</script>

External links in main domain :

1. https://www.patreon.com/bookwyrm
2. https://www.ramaytush.org/

Impact

1. This type of Phishing has huge potential for tricking users that click on external links from this(your) website to be a victim of a scam page because the redirecting is made in the background, while the user is focused on another tab.