HexBrain

Slack · Report #159460

Stored XSS(Cross Site Scripting) In Slack App Name

Validstatus
$1,000bounty
29upvotes
22 Nov 2016disclosed

How it was found

Hello Slack,

This vulnerability is about a Stored Cross Site Scripting

Slack Stored XSS In App(App Name)

Vulnerable URL(Edit App Page) https://api.slack.com/apps/[appid]/general

https://api.slack.com/apps/A21B3V9GA/general

Vulnerable Parameter = name

Note -Its also work on other user as well.

Send this link to victim

===================

Reproduction Steps POC Video - https://youtu.be/3jAbPjfPW1o Screen shot is also attached.

  1. Go to app edit page https://api.slack.com/apps/[appid]/general https://api.slack.com/apps/A21B3V9GA/general
  2. In app name parameter enter the following payload "/><script>alert(/Bhati/)</script>
  3. Now open the app page in any other tab https://bhativictim.slack.com/apps/A21B3V9GA--scriptalert-bhati-script
  4. You will get a Alert Box
  5. We can also send this same link to other user(victim).

Thanks, Narendra

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