Lock Cross-site Scripting

Auth0 is an authentication broker that supports both social and enterprise identity providers, including Active Directory, LDAP, Google Apps, and Salesforce. In versions before `11.33.0`, when the “additional signup fields� feature [is configured](https://github.com/auth0/lock#additional-sign-up-fields), a malicious actor can inject invalidated HTML code into these additional fields, which is then stored in the service `user_metdata` payload (using the `name` property). Verification emails, when applicable, are generated using this metadata. It is therefor possible for an actor to craft a malicious link by injecting HTML, which is then rendered as the recipient's name within the delivered email template. You are impacted by this vulnerability if you are using `auth0-lock` version `11.32.2` or lower and are using the “additional signup fields� feature in your application. Upgrade to version `11.33.0`. (2022-05-05, CVE-2022-29172)

auth0-lock is Auth0's signin solution. Versions of nauth0-lock before and including `11.30.0` are vulnerable to reflected XSS. An attacker can execute arbitrary code when the library's `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage` or the library's `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`. The vulnerability is patched in version 11.30.1. (2021-06-04, CVE-2021-32641)

In auth0-lock versions before and including 11.25.1, dangerouslySetInnerHTML is used to update the DOM. When dangerouslySetInnerHTML is used, the application and its users might be exposed to cross-site scripting (XSS) attacks. (2020-08-20, CVE-2020-15119)

Auth0 Lock before 11.21.0 allows XSS when additionalSignUpFields is used with an untrusted placeholder. (2020-02-03, CVE-2019-20174)

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>