CVE-2003-0287 in Movable Type
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Movable Type before 2.6, and possibly other versions including 2.63, allows remote attackers to insert arbitrary web script or HTML via the Name textbox, possibly when the "Allow HTML in comments?" option is enabled.
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Analysis
by VulDB Data Team • 05/03/2019
The vulnerability described in CVE-2003-0287 represents a classic cross-site scripting flaw that affected the Movable Type content management system prior to version 2.6. This type of vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is one of the most prevalent and dangerous web application security issues. The flaw specifically resides in how the application processes user input through the Name textbox field, particularly when the "Allow HTML in comments?" configuration option is enabled. This configuration setting creates a dangerous attack vector by permitting users to submit HTML content that should normally be sanitized before being rendered on web pages.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding mechanisms within the Movable Type application. When users submit data through the Name field, the application fails to properly sanitize or escape the input before displaying it in web pages, particularly in comment sections where HTML rendering is enabled. This allows malicious actors to inject arbitrary JavaScript code or HTML tags that execute in the context of other users' browsers who view the affected content. The vulnerability is particularly concerning because it operates at the user interface level where legitimate user interaction occurs, making it difficult to distinguish between benign and malicious input without proper validation.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it creates a persistent threat vector that can be exploited across multiple user sessions. Attackers can craft malicious payloads that redirect users to phishing sites, steal session cookies, or perform actions on behalf of authenticated users. The vulnerability affects not just individual users but can compromise entire user bases, especially in collaborative environments where multiple users interact through comments or content management features. When combined with the "Allow HTML in comments?" setting, the attack surface expands significantly as the application's trust model is violated, allowing untrusted input to be rendered as executable content.
Security mitigations for this vulnerability should focus on implementing comprehensive input validation and output encoding strategies that align with the OWASP Secure Coding practices. The most effective immediate solution involves sanitizing all user input before rendering it on web pages, particularly when HTML rendering is enabled. This includes implementing proper HTML escaping mechanisms, validating input against whitelists of allowed characters, and ensuring that any HTML content submitted by users is properly filtered to remove potentially dangerous elements. Additionally, the application should enforce strict separation between user-generated content and executable code, implementing Content Security Policies that prevent script execution from untrusted sources. Organizations should also consider implementing automated security scanning tools and regular vulnerability assessments to identify similar weaknesses in other applications. The remediation approach should follow the principle of least privilege, ensuring that user input is treated as untrusted until properly validated and sanitized according to established security standards such as those defined in the NIST Cybersecurity Framework.