Rocket.chat Cross-site Scripting

A cross-site scripting vulnerability exists in Rocket.chat CVE-2022-35251)

A link preview rendering issue in Rocket.Chat versions before 3.9 could lead to potential XSS attacks. (2021-10-18, CVE-2020-8291)

Rocket.Chat before 3.11, 3.10.5, 3.9.7, 3.8.8 is vulnerable to persistent cross-site scripting (XSS) using nested markdown tags allowing a remote attacker to inject arbitrary JavaScript in a message. This flaw leads to arbitrary file read and RCE on Rocket.Chat desktop app. (2021-03-26, CVE-2021-22886)

Rocket.Chat server before 3.9.0 is vulnerable to a self cross-site scripting (XSS) vulnerability via the drag & drop functionality in message boxes. (2021-01-26, CVE-2020-8292)

The `specializedRendering` function in Rocket.Chat server before 3.9.2 allows a cross-site scripting (XSS) vulnerability by way of the `value` parameter. (2021-01-26, CVE-2020-8288)

Rocket.Chat through 3.4.2 allows XSS where an attacker can send a specially crafted message to a channel or in a direct message to the client which results in remote code execution on the client side. (2020-08-18, CVE-2020-15926)

Rocket.Chat before 2.1.0 allows XSS via a URL on a ![title] line. (2019-10-21, CVE-2019-17220)

A reflected XSS issue was discovered in the registration form in Rocket.Chat before 0.66. When one creates an account, the next step will ask for a username. This field will not save HTML control characters but an error will be displayed that shows the attempted username unescaped via packages/rocketchat-ui-login/client/username/username.js in packages/rocketchat-ui-login/client/username/username.html. (2018-07-11, CVE-2018-13879)

An XSS issue was discovered in packages/rocketchat-mentions/Mentions.js in Rocket.Chat before 0.65. The real name of a username is displayed unescaped when the user is mentioned (using the @ symbol) in a channel or private chat. Consequently, it is possible to exfiltrate the secret token of every user and also admins in the channel. (2018-07-11, CVE-2018-13878)

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>