Trello: DOM based XSS via Wistia embedding

ID H1:111440
Type hackerone
Reporter reactors08
Modified 2016-01-20T14:20:31


Hi, You are using Wistia to embed video at However external script from vulnerable to XSS and allows to run malicious javascript on your side. vulnerable code:

I found that parameter wchannel can be controled to load js from[controled input].js example: browser tryied to load script from:

And now the only thing we need is to find the way how to upload malicious script to I wasnt able to upload something but i found that i can control outpoot of a json file via callback parameter:[video id].json?callback=[controlled outpoot] proof:

okay now we can attack trello: proof: