SonLogger before 6.4.1 is affected by Unauthenticated Arbitrary File Upload. An attacker can send a POST request to /Config/SaveUploadedHotspotLogoFile without any authentication or session header. There is no check for the file extension or content of the uploaded file.
https://www.sonlogger.com/releasenotes
https://github.com/erberkan/SonLogger-vulns
http://packetstormsecurity.com/files/161793/SonLogger-4.2.3.3-Shell-Upload.html