CVE-2002-1673 in Webmin
Summary
by MITRE
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.
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Analysis
by VulDB Data Team • 01/12/2025
The vulnerability identified as CVE-2002-1673 represents a critical cross-site scripting flaw in Webmin version 0.92's web interface. This issue stems from inadequate input sanitization and output encoding mechanisms within the web application's user interface components. The vulnerability specifically affects how the system handles script code execution within files that are rendered in the web interface, creating a pathway for malicious code injection attacks. The flaw is particularly concerning because it operates at the interface level where user inputs are directly processed and displayed without proper sanitization measures.
The technical implementation of this vulnerability occurs when local users can manipulate input fields that are subsequently displayed within the web interface. The most significant attack vector involves inserting malicious script code into user name fields within the passwd file, which is then rendered without proper HTML escaping or script sanitization. This creates a persistent cross-site scripting condition where any user who views the affected interface components becomes vulnerable to script execution. The vulnerability's impact is amplified by the fact that it operates within a privileged interface, potentially allowing attackers to access sensitive information including user cookies and session data.
This vulnerability directly maps to CWE-79 which describes Cross-Site Scripting flaws in web applications, and aligns with ATT&CK technique T1059.007 for script execution through web interfaces. The operational impact extends beyond simple script execution to include potential session hijacking and credential theft, as attackers can steal cookies from authenticated sessions. The vulnerability's exploitation requires local access to the system and knowledge of the webmin interface structure, making it particularly dangerous in environments where local user privileges are not properly restricted. The affected webmin interface components typically display user account information, system configuration details, and administrative functions where user inputs are rendered without proper output encoding.
The mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and output encoding mechanisms throughout the web interface. Webmin administrators should immediately upgrade to patched versions that properly sanitize user inputs and implement proper HTML escaping for all rendered content. Additionally, implementing proper access controls and privilege separation can limit the impact of such vulnerabilities. Network segmentation and monitoring of web interface access patterns can help detect potential exploitation attempts. The vulnerability demonstrates the critical importance of input validation in web applications and the need for consistent security practices across all interface components. Organizations should also consider implementing web application firewalls and regular security assessments to identify similar issues in other web-based administrative interfaces.