This article is a part of our Vulnerability Database (back to index)
Cross-site Scripting occurrences in Scratchtools
ScratchTools is a web extension designed to make interacting with the Scratch programming language community (Scratching) easier. In affected versions anybody who uses the Recently Viewed Projects feature is vulnerable to having their account taken over if they view a project that tries to. The issue is that if a user visits a project that includes Javascript in the title, then when the Recently Viewed Projects feature displays it, it could run the Javascript. This issue has been addressed in the 2.5.2 release. Users having issues scratching should open an issue in the project issue tracker https://github.com/STForScratch/ScratchTools/ (2022-06-27, CVE-2022-31094)
Why Cross-site Scripting can be dangerous
Cross site scripting is an attack where a web page executes code that is injected by an adversary. It usually appears, when users input is presented. This attack can be used to impersonate a user, take over control of the session, or even steal API keys.
The attack can be executed e.g. when you application injects the request parameter directly into the HTML code of the page returned to the user:
https://server.com/confirmation?message=Transaction+Complete
what results in:
<span>Confirmation: Transaction Complete</span>
In that case the message can be modified to become a valid Javascript code, e.g.:
https://server.com/confirmation?message=<script>dangerous javascript code here</script>
and it will be executed locally by the user's browser with full access to the user's personal application/browser data:
<span>Confirmation: <script>dangerous javascript code here</script></span>