An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO endpoint via a crafted header, when SSO is not configured. An attacker can create a valid and authenticated session that can be used to perform any actions in the name of other users.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26030
Reference (s):
- https://zammad.com/news/security-advisory-zaa-2020-18