Vulnerabilities

Webmin accepts basic authentication without session cookies when an attacker provides the 'User-Agent: webmin' header, allowing bypass of additional MFA requirements. Fixed in 2.640.

Webmin before 2.641 contains a stored cross-site scripting vulnerability in the email template description field of the System and Server Status module that allows low-privileged authenticated attackers to execute arbitrary JavaScript in the browser context of administrators by injecting unsanitized input stored in save_tmpl.cgi and rendered unescaped in list_tmpls.cgi.

Webmin 2.510 is vulnerable to a Host Header Injection in the password reset functionality (forgot_send.cgi). The reset link sent to users is constructed using the HTTP Host header via get_webmin_email_url(). An attacker can manipulate the Host header to inject a malicious domain into the reset email. If a victim follows the poisoned link, the attacker can intercept the reset token and gain full control of the target account.

Webmin, a widely used web-based administration tool for Unix and Linux servers, contains an OS command injection flaw (CWE-78, ZDI-CAN-22346) in its handling of CGI requests: a user-supplied string is not properly validated before being used in a system call. An attacker with valid low-privilege credentials can trigger the flaw remotely by sending a crafted CGI request with injected shell commands. Successful exploitation yields arbitrary code execution in the context of root, giving the attacker full control over the affected host. Any organization running Webmin whose web interface is reachable from a network the attacker can access is in scope, including instances exposed to the internet on the default port 10000. No public proof-of-concept or CISA KEV listing exists yet, but EPSS assigns a 33.5% probability of exploitation within 30 days (98th percentile), indicating a meaningful near-term threat.

Do: Upgrade Webmin to the fixed release identified in the vendor/ZDI advisory as soon as possible; the available data does not state specific affected or fixed version numbers, so verify the fixed version in Webmin's release notes. Until patched, restrict access to the Webmin interface (default TCP 10000) to trusted networks or a VPN, and audit which accounts hold Webmin credentials since valid authentication is required to exploit. Review web-server and Webmin logs for anomalous CGI requests containing shell metacharacters that could indicate exploitation attempts.

A discrepancy in error messages for invalid login attempts in Webmin Usermin v2.100 allows attackers to enumerate valid user accounts.

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 exists in session_login.cgi of Webmin versions prior to 1.970 and Usermin versions prior to 1.820. If this vulnerability is exploited, an arbitrary script may be executed on the web browser of the user who accessed the website using the product. As a result, a webpage may be altered or sensitive information such as a credential may be disclosed.

Improper handling of insufficient permissions or privileges vulnerability exists in ajaxterm module of Webmin prior to 2.003. If this vulnerability is exploited, a console session may be hijacked by an unauthorized user. As a result, data within a system may be referred, a webpage may be altered, or a server may be permanently halted.

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.

Multiple stored cross-site scripting (XSS) vulnerabilities in Usermin 2.000 allow remote attackers to inject arbitrary web script or HTML via the folder name parameter while creating the folder to manage the folder tab, filter tab, and forward mail tab.

A reflected cross-site scripting (XSS) vulnerability in the File Manager function of Webmin v2.100 allows attackers to execute malicious scripts via injecting a crafted payload into the Find in Results file.

A Stored Cross-Site Scripting (XSS) vulnerability in the SSH configuration tab in Usermin 2.001 allows remote attackers to inject arbitrary web script or HTML via the key name field while adding an authorized key.

A Reflected Cross-site scripting (XSS) vulnerability in the file manager tab in Usermin 2.000 allows remote attackers to inject arbitrary web script or HTML via the file mask field while searching under the tools drop down.

Multiple stored cross-site scripting (XSS) vulnerabilities in Usermin 2.000 allow remote attackers to inject arbitrary web script or HTML via the key comment to different pages such as public key details, Export key, sign key, send to key server page, and fetch from key server page tab.

A Reflected Cross-site scripting (XSS) vulnerability in the file manager tab in Usermin 2.000 allows remote attackers to inject arbitrary web script or HTML via the replace in results field while replacing the results under the tools drop down.

A Stored Cross-Site Scripting (XSS) vulnerability in the SSH configuration tab in Usermin 2.001 allows remote attackers to inject arbitrary web script or HTML via options for the host value while editing the host options.

An issue was discovered in Webmin 2.021. A Reflected Cross-Site Scripting (XSS) vulnerability was discovered in the package search functionality. The vulnerability allows an attacker to inject a malicious payload in the "Search for Package" field, which gets reflected back in the application's response, leading to the execution of arbitrary JavaScript code within the context of the victim's browser.

A vulnerability, which was classified as problematic, was found in Webmin 2.001. Affected is an unknown function of the file xterm/index.cgi. The manipulation leads to basic cross site scripting. It is possible to launch the attack remotely. Upgrading to version 2.003 is able to address this issue. The patch is identified as d3d33af3c0c3fd3a889c84e287a038b7a457d811. It is recommended to upgrade the affected component. VDB-212862 is the identifier assigned to this vulnerability.

Usermin through 1.850 allows a remote authenticated user to execute OS commands via command injection in a filename for the GPG module.

The Read Mail module in Webmin 1.995 and Usermin through 1.850 allows XSS via a crafted HTML e-mail message.

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.

A Cross-Site Scripting (XSS) vulnerability exists in Webmin 1.973 via the Scheduled Cron Jobs feature.