This article is about a security bug/issue I found on a managed private program at H1(Hackerone).
Yes it was a CSV injection. If you don’t know what CSV injection or formula injection is ? Let me summarise it for you.
The excel software allow user to insert the formulas in excel sheet but sometime if web application(if web app have any functionality which generates CSV file) let anyone to insert the untrusted data into this CSV file, anyone can inject the malicious formulas which can run when user open that CSV file in excel software.
For more info on CSV injection visit below links
https://www.owasp.org/index.php/CSV_Injection
https://payatu.com/csv-injection-basic-to-exploit/
Affected Functionality:-
The user can download all the comments(data) on his/her articles as a CSV file.
Now anyone can inject the formula (payload) as a comment on the article.
e.g. the payload I used in report.
=HYPERLINK (’www.BadSite.com’)
Now when user download the data(comments) as a CSV file and open the file. The payload will be triggered and a web browser will be open with above website.
Reward/Bounty:-
The bug/issue is fixed now and the program does not offers bounty. All i got +7 repo points.
The feedback/comments are welcomed.
