CVE-2017-17089 in Webmin
Summary
by MITRE
custom/run.cgi in Webmin before 1.870 allows remote authenticated administrators to conduct XSS attacks via the description field in the custom command functionality.
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Analysis
by VulDB Data Team • 01/19/2023
The vulnerability CVE-2017-17089 represents a cross-site scripting flaw in Webmin versions prior to 1.870 that specifically affects the custom command functionality. This issue exists within the custom/run.cgi component of the web-based system administration tool, where authenticated administrators can exploit the vulnerability by injecting malicious scripts into the description field of custom commands. The flaw demonstrates a classic input validation weakness that allows malicious code execution in the context of other users' browsers, making it particularly dangerous in shared administrative environments where multiple users access the same Webmin interface.
The technical implementation of this vulnerability stems from insufficient sanitization of user input within the description field parameter. When an authenticated administrator creates or modifies a custom command, the system fails to properly escape or validate special characters that could be interpreted as HTML or JavaScript code. This allows an attacker who has gained administrative privileges to craft malicious payloads that will execute in the browsers of other users who view the affected custom command listings. The vulnerability is classified as a reflected cross-site scripting issue under CWE-79, which specifically addresses the improper handling of untrusted data in web applications.
The operational impact of this vulnerability extends beyond simple script injection, as it can be leveraged to escalate privileges or conduct further attacks within the compromised environment. An attacker with administrative access could craft a malicious description that, when viewed by other administrators or users, would execute malicious JavaScript code in their browsers. This code could potentially steal session cookies, redirect users to malicious sites, or perform actions on behalf of the victim within the Webmin interface. The vulnerability affects the integrity and confidentiality of the web application's user interface and can be particularly problematic in enterprise environments where multiple administrators share the same system. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1566 (Phishing) as it enables malicious code execution and social engineering attacks through the web interface.
Mitigation strategies for CVE-2017-17089 focus on immediate patching of Webmin to version 1.870 or later, where the input sanitization issues have been resolved. Organizations should also implement strict input validation procedures that enforce proper escaping of special characters in all user-editable fields, particularly those that are rendered in web browsers. Additional protective measures include implementing content security policies to prevent unauthorized script execution, conducting regular security audits of web applications, and ensuring that administrative privileges are granted only to trusted users. Network segmentation and monitoring of administrative access patterns can also help detect potential exploitation attempts. The vulnerability highlights the importance of proper input validation and output encoding in web applications, reinforcing the need for security-conscious development practices and regular vulnerability assessments to prevent similar issues in other software components.