GHSA-jr3j-whm4-9wwm Reflected XSS when using flashMessages or languageDictionary

• npm auth0-lock: < 11.30.1 → fixed in 11.30.1

Overview Versions 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`. • `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`. Am I affected? You are affected by this vulnerability if you are using `auth0-lock` version `11.30.0` or lower and all of the following conditions apply: • You are utilizing `flashMessage` feature. • User input or data from URL parameters is incorporated into the `flashMessage`. An example of a vulnerable snippet where query parameters are used to populate the `text` property of a `flashMessage`. ```js var params = new URLSearchParams(location.search); var errorMessage = params.get('error__message'); var showParams = {}; if (!!errorMessage === true) { showParams.flashMessage = { type: 'error', text: 'We were unable to log you in. ' + errorMessage, }; } lock.show(showParams); ``` OR • You are utilizing `languageDictionary` feature. • User input or data from URL parameters is used in `languageDictionary` properties. An example of a vulnerable snippet where query parameters are used to populate the `socialLoginInstructions` property of a `languageDictionary`. ```js var params = new URLSearchParams(location.search); var instruction = params.get('instruction'); var options = { languageDictionary: { emailInputPlaceholder: "[email protected]", title: "title", socialLoginInstructions: instruction }, }; var lock = new Auth0LockPasswordless( CLIENT_ID, DOMAIN, options ); lock.show() ``` How to fix that? Upgrade to version `11.30.1`. Will this update impact my users? The fix uses DOMPurify to sanitise the `flashMessage` and `languageDictionary` inputs. If you are including inline JavaScript in these fields, like `script` tags or `onclick` attributes, these will be removed.