HexBrain

Imgur · Report #484434

Stored XSS on imgur profile

Validstatus
mediumseverity
614upvotes
2 Mar 2019disclosed

How it was found

Hello, I submitted a report on imgur, but the staff marked it as duplicate. #482841 I reviewed the report of the first submitted report. #381553 We are on the same situation and his case is already fixed because I tried visiting his site too which is https://12test.imgur.com/ and even redoing his steps to reproduce but no XSS is triggered. And I have a different bypass and my bypass succeed. I can still fire up XSS on the said webpage.

Sorry for double posting, but I think his case #381553 is already fixed and mine is different.

There are still bypasses exists in the imgur create album that can cause an Stored XSS. Try to visit my site: https://gidsumaya.imgur.com/ and XSS will trigger. F410962:

In my case, I bypassed the filtering using HTML entities for the alternation of <>, because I noticed that it's filtering the <>.

Payload:

”/>&_lt;_script>alert(1)&_lt;/scr_ipt&gt”/> remove the underscores.

And I can still fire up XSS and anyone who visits the link, the XSS will trigger.

I acknowledge that there was another report, for the same issue but that I still have a way to bypass whatever fix they implemented.

Impact

XSS can use to steal cookies, password or to run arbitrary code on victim's browser

This report was disclosed publicly on HackerOne and belongs to its author and the program. See the original