Arbitrary command execution can occur in Webmin through 1.962. Any user authorized for the Package Updates module can execute arbitrary commands with root privileges via vectors involving %0A and %0C. NOTE: this issue exists because of an incomplete fix for CVE-2019-12840.
https://www.webmin.com/download.html
https://www.pentest.com.tr/exploits/Webmin-1962-PU-Escape-Bypass-Remote-Command-Execution.html
https://www.exploit-db.com/exploits/49318
http://packetstormsecurity.com/files/160676/Webmin-1.962-Remote-Command-Execution.html