Webmin is a web-based system administration tool for Unix-like servers. Prior to version 2.640, for Webmin accounts that require a second authentication factor (typically TOTP), an attacker with knowledge of the username and password can bypass the 2FA requirement by using Basic authentication. Webmin is a web-based system administration tool for Unix-like servers. As a workaround, apply the patch from commit da18a16c84ae5c0b78cad79609cb0efb174000ec manually.

The Webmin HTTP server (miniserv.pl) allows unauthenticated attackers to impersonate any user with a configured SSL client certificate by sending a forged HTTP header. A remote attacker can spoof certificate DNs and authenticate as any user. Fixed in 2.202.

Webmin allows unauthenticated attackers to read the contents of any file ending in .conf within module directories, due to a bypassable regex pattern.

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 2.640 does not safely construct a filename for saving of an attachment within the mailboxes component. This occurs in mailboxes/detachall.cgi.

Webmin before 2.640 allows mailboxes/detach.cgi XSS via an SVG document attachment that is viewed in the mailboxes component, because image/svg+xml is used instead of a safe type (e.g., text/plain).

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 savetmpl.cgi and rendered unescaped in listtmpls.cgi.

squid/cachemgr.cgi in Webmin before 2.600 does not properly quote arguments. This is relevant if Webmin's Squid module and its Cache Manager feature are available, and an untrusted party is able to authenticate to Webmin and has certain Cache Manager permissions (the "cms" security option).

Webmin 2.510 is vulnerable to a Host Header Injection in the password reset functionality (forgotsend.cgi). The reset link sent to users is constructed using the HTTP Host header via getwebminemailurl(). 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.

This vulnerability allows remote attackers to escalate privileges on affected installations of Webmin. Authentication is required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 8.8. The following CVEs are assigned: CVE-2025-2774.

This vulnerability allows remote attackers to escalate privileges on affected installations of Webmin. Authentication is required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 8.8. The following CVEs are assigned: CVE-2025-2774.

Usermin 0.980 through 1.x before 1.660 allows uconfigsave.cgi sigfilefree remote code execution because it uses the two argument (not three argument) form of Perl open.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Webmin. Authentication is required to exploit this vulnerability. The specific flaw exists within the handling of CGI requests. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Webmin. Authentication is required to exploit this vulnerability. The specific flaw exists within the handling of CGI requests. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Webmin. Authentication is required to exploit this vulnerability. The specific flaw exists within the handling of CGI requests. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root.

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

Webmin is a web-based system administration tool for Unix-like servers, and services with about 1,000,000 yearly installations worldwide.

Webmin/Virtualmin use a UDP service discovery, usually running on port UDP/10000. This service responds to any UDP request with the IP address and port on which the control panel is available.

This behavior can be used to implement a Loop DoS attack (CVE-2024-2169 etc) by sending udp packets with spoofed source ip:port using other Webmin instance IP-andreess that can lead to endless traffic exchange between hosts, Denial of Service (DOS) and/or abuse of resources.

Fix: Users are recommended to upgrade to version Webmin 2.202, Virtualmin 7.20.2 which fixes the issue.

Workaround: Block UDP/10000 the service for access from the Internet.

References: https://webmin.com/ https://cispa.de/en/loop-dos https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-2169

Credits: Alexander Chernenkov, Sergey Gordeychik, CyberOK

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 sessionlogin.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.

Cross-site request forgery vulnerability exists in ajaxterm module of Webmin versions prior to 2.003. If this vulnerability is exploited, unintended operations may be performed when a user views a malicious page while logged in. As a result, data within a system may be referred, a webpage may be altered, or a server may be permanently halted.

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 exists in sysinfo.cgi of Webmin versions prior to 1.910. 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 session ID may be obtained, a webpage may be altered, or a server may be 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 Replace in Results file.

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 Usermin Configuration function of Webmin v2.100 allows attackers to execute arbitrary web sripts or HTML via a crafted payload injected into the Custom field.

A stored cross-site scripting (XSS) vulnerability in Webmin v2.100 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the cloned module name parameter.

An issue was discovered in Webmin 2.100. The File Manager functionality allows an attacker to exploit a Cross-Site Scripting (XSS) vulnerability. By providing a malicious payload, an attacker can inject arbitrary code, which is then executed within the context of the victim's browser when any file is searched/replaced.