CVE-2002-0682 in Tomcat
Summary
by MITRE
Cross-site scripting vulnerability in Apache Tomcat 4.0.3 allows remote attackers to execute script as other web users via script in a URL with the /servlet/ mapping, which does not filter the script when an exception is thrown by the servlet.
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Analysis
by VulDB Data Team • 12/05/2024
The vulnerability described in CVE-2002-0682 represents a critical cross-site scripting flaw within Apache Tomcat version 4.0.3 that fundamentally undermines web application security. This issue manifests when the servlet container processes requests through the /servlet/ mapping path and fails to properly sanitize user input during exception handling scenarios. The vulnerability exploits the lack of input validation in the error handling mechanism, allowing malicious actors to inject malicious scripts that execute in the context of other users' browsers. The flaw specifically occurs when an exception is thrown by the servlet component, creating an opportunity for attackers to manipulate the URL parameters and inject harmful JavaScript code that gets executed in the victim's browser session. This type of vulnerability directly violates the principle of least privilege and demonstrates a fundamental failure in the application's input sanitization processes.
The technical implementation of this vulnerability stems from improper handling of exception states within the Tomcat servlet container's request processing pipeline. When a servlet encounters an error condition, the normal flow of execution is interrupted and an exception is thrown, but the system fails to properly escape or filter user-supplied data that may be included in the error response. The /servlet/ mapping path serves as the attack vector because it represents a standard entry point for servlet processing, making it a commonly targeted location for exploitation attempts. This flaw operates under the Common Weakness Enumeration category CWE-79, which specifically addresses Cross-Site Scripting vulnerabilities, and aligns with the ATT&CK technique T1203 - Exploitation for Client Execution. The vulnerability's exploitation requires minimal privileges since it targets the web application layer rather than requiring system-level access, making it particularly dangerous in environments where multiple users interact with the same web application.
The operational impact of this vulnerability extends far beyond simple data theft or defacement, as it enables attackers to perform session hijacking, steal sensitive user information, and potentially escalate privileges within the web application. Successful exploitation allows remote attackers to inject malicious scripts that execute with the privileges of the affected user, potentially leading to complete account compromise and unauthorized access to sensitive data. The vulnerability affects all users of the affected Tomcat version who are logged into the web application, creating a broad attack surface that can be exploited across multiple user sessions simultaneously. Organizations using this vulnerable version face significant risk of data breaches, as the malicious scripts can capture cookies, session tokens, and other sensitive information transmitted between the user's browser and the web server. This vulnerability also enables attackers to perform actions on behalf of legitimate users, potentially leading to unauthorized transactions, data modification, or complete system compromise through session manipulation.
Organizations affected by CVE-2002-0682 should immediately implement multiple layers of mitigation strategies to protect their web applications. The primary recommendation involves upgrading to a patched version of Apache Tomcat that addresses this specific vulnerability, as version 4.1.18 and later contain the necessary fixes for proper input sanitization during exception handling. Additionally, implementing proper input validation at all entry points, including URL parameters and servlet mappings, provides an additional layer of defense. Web Application Firewalls should be configured to detect and block suspicious script injection attempts, while proper output encoding techniques should be implemented to ensure that any user-supplied data is properly escaped before being rendered in web pages. Organizations should also consider implementing Content Security Policy headers to limit script execution and prevent unauthorized code injection. The vulnerability's classification under CWE-79 and its alignment with ATT&CK technique T1203 emphasize the need for comprehensive security measures that address both the immediate exploit and broader defensive strategies to prevent similar issues in the future.