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.