Description
bw-calendar-engine version <= bw-calendar-engine-3.12.0 contains a XML External Entity (XXE) vulnerability in IscheduleClient XML Parser that can result in Disclosure of confidential data, denial of service, SSRF, port scanning. This attack appear to be exploitable via Man in the Middle or malicious server.
Remediation
References
https://0dd.zone/2018/10/28/bw-calendar-engine-XXE-MitM/
https://github.com/Bedework/bw-calendar-engine/issues/3