Monstra CMS through 3.0.4 allows remote authenticated users to take over arbitrary user accounts via a modified login parameter to an edit URI, as demonstrated by login=victim to the users/21/edit URI.
http://uploadboy.me/cn40ne6p89t6/POC.mp4.html
https://cert.ikiu.ac.ir/public-files/pages/attachments/11/02630f153869936d555a79f89d717f9c.pdf
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8439