# 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:
![](https://raw.githubusercontent.com/AGNIHACKERS/agnihackers.github.io/main/Proof/Tabnabbing/POC.jpg)
# POC Screenshot 2:
![](https://raw.githubusercontent.com/AGNIHACKERS/agnihackers.github.io/main/Proof/Tabnabbing/POC%202.jpg)
# MITIGATIONS:-
In order to mitigate this issue, developers are encouraged to use rel=”nofollow noopener noreferrer” as follows:
\
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:
# External links in main domain :
1. “https://www.patreon.com/bookwyrm“
2. “https://www.ramaytush.org/“Read More