Gravityforms Cross-site Scripting

A stored Cross-Site Scripting (XSS) vulnerability in forms import feature in Rocketgenius Gravity Forms before 2.4.21 allows remote attackers to inject arbitrary web script or HTML via the import of a GF form. This code is interpreted by users in a privileged role (Administrator, Editor, etc.). (2021-01-20, CVE-2020-27850)

A stored Cross-Site Scripting (XSS) vulnerability in the survey feature in Rocketgenius Gravity Forms before 2.4.21 allows remote attackers to inject arbitrary web script or HTML via a textarea field. This code is interpreted by users in a privileged role (Administrator, Editor, etc.). (2021-01-20, CVE-2020-27852)

Multiple stored HTML injection vulnerabilities in the "poll" and "quiz" features in an additional paid add-on of Rocketgenius Gravity Forms before 2.4.21 allows remote attackers to inject arbitrary HTML code via poll or quiz answers. This code is interpreted by users in a privileged role (Administrator, Editor, etc.). (2021-01-20, CVE-2020-27851)

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>