Published On: 24 Oct 2019
The bug was found initially in the ask me a question section of the app, but later on we found out that any livestream on instagram automatically has an ask me a question section, extending the impact of the bug to the livestream service too
Since no back-end checks where in place, an attacker could crash a victim's app by sending a very large request as a question.
-Crash victim's app when opening notifications section -Crash victim's app while live streaming -Crash victim's app when checking their stories questionnaire section
Step
1
Find a user thats live streaming and send a question to their live stream
Step
2
Capture the request and you will find a parameter:
&text=your_question
change the your_question part to a very large text
now forward the request
The same attack could be done on a regular story with a questionnaire in it. That way the attack will crash the victim's app when opening the questions of this story, and the notifications section, as the question appears in the notifications section