Описание
HTML injection in search results via plaintext message highlighting
Impact
Plain text messages containing HTML tags are rendered as HTML in the search results. To exploit this, an attacker needs to trick a user into searching for a specific message containing an HTML injection payload.
Cross-site scripting is possible by including resources from recaptcha.net and gstatic.com which are included in the default CSP.
Thanks to Cadence Ember for finding the injection and to S1m for finding possible XSS vectors.
Patches
Version 3.71.0 of the SDK fixes the issue.
Workarounds
Restarting the client will clear the injection.
Ссылки
Пакеты
matrix-react-sdk
< 3.71.0
3.71.0
Связанные уязвимости
matrix-react-sdk is a react-based SDK for inserting a Matrix chat/VoIP client into a web page. Prior to version 3.71.0, plain text messages containing HTML tags are rendered as HTML in the search results. To exploit this, an attacker needs to trick a user into searching for a specific message containing an HTML injection payload. No cross-site scripting attack is possible due to the hardcoded content security policy. Version 3.71.0 of the SDK patches over the issue. As a workaround, restarting the client will clear the HTML injection.