Zammad before 3.3.1, when Domain Based Assignment is enabled, relies on a claimed e-mail address for authorization decisions. An attacker can register a new account that will have access to all tickets of an arbitrary Organization.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-14214
Reference (s):
- https://github.com/zammad/zammad/commit/40148392426f626cb779c76d6bdda0f67bd6069d
- https://zammad.com/news/security-advisory-zaa-2020-12