CVE-2008-7140 in @lex Guestbook
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in @lex Guestbook 4.0.5 and earlier allow remote attackers to inject arbitrary web script or HTML via the (1) language_setup parameter to setup.php or (2) test parameter to index.php. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information. NOTE: a third party has been reported that the test parameter is not used in @lex Guestbook.
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Analysis
by VulDB Data Team • 03/06/2025
The CVE-2008-7140 vulnerability represents a critical cross-site scripting flaw affecting @lex Guestbook versions 4.0.5 and earlier, demonstrating the persistent security challenges inherent in web application development. This vulnerability stems from inadequate input validation and sanitization mechanisms within the application's parameter handling processes. The flaw specifically manifests when the application fails to properly sanitize user-supplied data passed through the language_setup parameter in setup.php and the test parameter in index.php, creating exploitable entry points for malicious actors seeking to inject arbitrary web scripts or HTML content.
The technical implementation of this vulnerability aligns with CWE-79, which categorizes cross-site scripting as a code injection flaw where untrusted data is incorporated into web pages without proper validation or encoding. When an attacker crafts malicious input containing script tags or other HTML content and submits it through either of the vulnerable parameters, the application processes this unvalidated data and subsequently renders it within the web page context. This creates a persistent XSS vector where the injected code executes in the victim's browser, potentially leading to session hijacking, credential theft, or redirection to malicious sites. The vulnerability's impact is amplified by the fact that it affects core application setup and testing functionality, making it particularly dangerous as it can be exploited during normal application usage or configuration processes.
The operational implications of this vulnerability extend beyond simple data corruption or display issues, as it fundamentally compromises user trust and application integrity. Attackers can leverage this vulnerability to execute malicious scripts in the context of authenticated users, potentially gaining access to sensitive session information or performing unauthorized actions on behalf of victims. The fact that the test parameter may not be actively used in the application, as noted in the vulnerability description, suggests that the vulnerability could be present in the codebase even if not immediately exploitable through normal user workflows. This highlights the importance of comprehensive code review and input validation practices throughout all application components, not just those deemed critical or frequently used. The vulnerability also demonstrates how legacy applications, particularly those with outdated security practices, remain susceptible to well-known attack vectors that should have been addressed through proper security development lifecycle implementation.
Effective mitigation strategies for CVE-2008-7140 require immediate remediation through proper input validation and output encoding mechanisms. The primary solution involves implementing strict sanitization of all user-supplied parameters, particularly those used in setup and configuration processes where input validation is often insufficient. Applications should employ context-appropriate encoding techniques such as HTML entity encoding for output rendering, and implement proper parameter validation using allowlists rather than denylists. Additionally, organizations should consider implementing web application firewalls to provide additional layers of protection, though this should not replace proper code-level fixes. The vulnerability also underscores the importance of regular security assessments and penetration testing to identify similar issues in legacy systems, as well as the need for comprehensive security training for developers to prevent such flaws in future development cycles. Organizations should also implement proper patch management processes to ensure timely updates to vulnerable applications, particularly when dealing with known security issues in widely used open source components.