The web interface for Webmin 0.92 does not properly quote or filter script code in files that are displayed to the interface, which allows local users to execute script and possibly steal cookies by inserting the script into certain files or fields, such as a real user name entry in the passwd file.
The Printer Administration module for Webmin 0.990 and earlier allows remote attackers to execute arbitrary commands via shell metacharacters in the printer name.
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.
Webmin before 0.5 does not restrict the number of invalid passwords that are entered for a valid username, which could allow remote attackers to gain privileges via brute force password cracking.