Zulip is an open-source team collaboration tool. Versions 2.1.0 through and including 5.2 are vulnerable to a logic error. A stream configured as private with protected history, where new subscribers should not be allowed to see messages sent before they were subscribed, when edited causes the server to incorrectly send an API event that includes the edited message to all of the stream’s current subscribers. This API event is ignored by official clients, but can be observed by using a modified client or the browser’s developer tools. This bug will be fixed in Zulip Server 5.3. There are no known workarounds.
Add your gear to cvedb and we'll alert you only when zulip ships something exploited.
Check my exposure →This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.