The RPC module in Webmin 0.21 through 0.99, when installed without root or admin privileges, allows remote attackers to read and write to arbitrary files and execute arbitrary commands via remote_foreign_require and remote_foreign_call requests.
http://www.securiteam.com/unixfocus/5CP0R1P80G.html
http://www.iss.net/security_center/static/9983.php
http://www.derkeiler.com/Mailing-Lists/securityfocus/bugtraq/2002-08/0403.html