The control panel in ASP Calendar does not require authentication to access, which allows remote attackers to gain unauthorized access via a direct request to main.asp.
https://exchange.xforce.ibmcloud.com/vulnerabilities/18474
http://marc.info/?l=bugtraq&m=110304839629822&w=2
Source: Mitre, NVD
Published: 2004-12-31
Updated: 2017-07-11
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Severity: High
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical