CVE-2003-1136 in Guestbook
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Chi Kien Uong Guestbook 1.51 allows remote attackers to inject arbitrary web script or HTML via (1) HTML in a posted message or (2) Javascript in an onmouseover attribute in an e-mail address or URL.
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Analysis
by VulDB Data Team • 07/20/2025
The vulnerability described in CVE-2003-1136 represents a classic cross-site scripting flaw in the Chi Kien Uong Guestbook version 1.51 web application. This type of vulnerability falls under the Common Weakness Enumeration category CWE-79 which specifically addresses improper neutralization of input during web page generation, making it a fundamental security weakness in web application development. The vulnerability exists within the guestbook application's handling of user-submitted content, where the system fails to properly sanitize or escape user input before rendering it in web pages, creating an environment where malicious scripts can be executed in the context of other users' browsers.
The technical exploitation of this vulnerability occurs through two primary vectors that demonstrate the application's inadequate input validation mechanisms. The first attack vector involves injecting HTML content directly into posted messages, while the second vector exploits the onmouseover javascript attribute within email addresses or URLs. Both methods exploit the same underlying flaw where user-supplied data is not properly escaped or filtered before being rendered in the web interface. This allows an attacker to craft malicious payloads that, when viewed by other users, execute in their browser context, potentially leading to session hijacking, credential theft, or redirection to malicious sites.
The operational impact of this vulnerability extends beyond simple script execution, as it fundamentally undermines the security model of the guestbook application. When users view maliciously crafted messages, their browsers execute the injected scripts with the privileges of the victim user, potentially allowing attackers to access session cookies, modify content, or redirect users to phishing sites. The vulnerability affects all users who view the compromised guestbook entries, making it particularly dangerous in environments where multiple users interact with the application. This type of vulnerability is classified under the MITRE ATT&CK framework as part of the T1059.007 technique for Command and Scripting Interpreter: JavaScript, demonstrating how attackers can leverage web-based scripting to compromise user sessions and data.
Mitigation strategies for this vulnerability must address the core issue of input sanitization and output encoding. Organizations should implement proper input validation that strips or escapes potentially dangerous characters and attributes from user submissions. The application should employ comprehensive output encoding for all user-generated content before rendering it in web pages, particularly focusing on HTML and JavaScript contexts. Additionally, implementing a Content Security Policy (CSP) header can provide an additional layer of protection against script execution, while regular security audits and code reviews should be conducted to identify similar vulnerabilities in other parts of the application. The remediation process should also include proper error handling and logging mechanisms to detect potential exploitation attempts, ensuring that the guestbook application follows secure coding practices as outlined in OWASP Top Ten and other industry security standards.