Webmin before 2.202 and Virtualmin before 7.20.2 allow a network traffic loop via spoofed UDP packets on port 10000.

Cross Site Scripting vulnerability (XSS) in webmin v.2.105 and earlier allows a remote attacker to execute arbitrary code via a crafted payload to the "Execute cron job as" tab Input field.

There is a stored cross-site scripting (XSS) vulnerability in Webmin 2.002 and below via the Cluster Cron Job tab Input field, which allows attackers to run malicious scripts by injecting a specially crafted payload.

software/apt-lib.pl in Webmin before 1.997 lacks HTML escaping for a UI command.

Webmin through 1.991, when the Authentic theme is used, allows remote code execution when a user has been manually created (i.e., not created in Virtualmin or Cloudmin). This occurs because settings-editor_write.cgi does not properly restrict the file parameter.

Improper Authorization in GitHub repository webmin/webmin prior to 1.990.

Improper Access Control to Remote Code Execution in GitHub repository webmin/webmin prior to 1.990.

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.

An Improper Data Validation Vulnerability exists in Webmin 1.941 and earlier affecting the Command Shell Endpoint. A user may enter HTML code into the Command field and submit it. Then, after visiting the Action Logs Menu and displaying logs, the HTML code will be rendered (however, JavaScript is not executed). Changes are kept across users.

An XSS Vulnerability exists in Webmin 1.941 and earlier affecting the Cluster Shell Commands Endpoint. A user may enter any XSS Payload into the Command field and execute it. Then, after revisiting the Cluster Shell Commands Menu, the XSS Payload will be rendered and executed.

XSS exists in Webmin 1.941 and earlier affecting the Save function of the Read User Email Module / mailboxes Endpoint when attempting to save HTML emails. This module parses any output without sanitizing SCRIPT elements, as opposed to the View function, which sanitizes the input correctly. A malicious user can send any JavaScript payload into the message body and execute it if the user decides to save that email.