Vulnerabilidades

Zulip Server before 2.1.5 allows reflected XSS via the Dropbox webhook.

Zulip Server before 2.1.3 allows XSS via the modal_link feature in the Markdown functionality.

Zulip Server before 2.1.3 allows reverse tabnabbing via the Markdown functionality.

Zulip Server before 2.1.3 allows XSS via a Markdown link, with resultant account takeover.

The image thumbnailing handler in Zulip Server versions 1.9.0 to before 2.0.8 allowed an open redirect that was visible to logged-in users.

In Zulip Server versions from 1.7.0 to before 2.0.7, a bug in the new user signup process meant that users who registered their account using social authentication (e.g., GitHub or Google SSO) in an organization that also allows password authentication could have their personal API key stolen by an unprivileged…

Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files. A user who is logged into the server could upload files of certain types to mount a stored cross-site scripting attack on other logged-in users. On a Zulip server using the default local uploads backend, the attack is only effective…

The Markdown parser in Zulip server before 2.0.5 used a regular expression vulnerable to exponential backtracking. A user who is logged into the server could send a crafted message causing the server to spend an effectively arbitrary amount of CPU time and stall the processing of future messages.

In Zulip Server versions before 1.7.2, there was an XSS issue with user uploads and the (default) LOCAL_UPLOADS_DIR storage backend.

In Zulip Server versions before 1.7.2, there was an XSS issue with stream names in topic typeahead.

In Zulip Server versions 1.5.x, 1.6.x, and 1.7.x before 1.7.2, there was an XSS issue with muting notifications.

In Zulip Server versions before 1.7.2, there were XSS issues with the frontend markdown processor.

In Zulip Server before 1.7.1, on a server with multiple realms, a vulnerability in the invitation system lets an authorized user of one realm on the server create a user account on any other realm.

Zulip Server 1.5.1 and below suffer from an error in the implementation of the invite_by_admins_only setting in the Zulip group chat application server that allowed an authenticated user to invite other users to join a Zulip organization even if the organization was configured to prevent this.

An error in the implementation of an autosubscribe feature in the check_stream_exists route of the Zulip group chat application server before 1.4.3 allowed an authenticated user to subscribe to a private stream that should have required an invitation from an existing member to join. The issue affects all previously…