CVE-2009-2104 in Modern Guest Book Commenting System
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the Modern Guestbook / Commenting System (ve_guestbook) extension 2.7.1 and earlier for TYPO3 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 12/10/2017
The CVE-2009-2104 vulnerability represents a critical cross-site scripting flaw within the Modern Guestbook / Commenting System extension for TYPO3 content management platform. This vulnerability affects versions 2.7.1 and earlier, making it a significant security concern for TYPO3 installations that rely on this guestbook functionality. The flaw enables remote attackers to execute malicious web scripts or HTML code within the context of affected websites, potentially compromising user sessions and data integrity. The vulnerability stems from inadequate input validation and output sanitization mechanisms within the extension's comment submission and display processes.
The technical exploitation of this XSS vulnerability occurs through unspecified vectors that likely involve the handling of user-submitted comments or guestbook entries. When users submit content through the guestbook system, the extension fails to properly sanitize or encode the input before rendering it on web pages. This allows attackers to inject malicious scripts that execute in the browsers of other users who view the compromised guestbook entries. The vulnerability manifests as a classic reflected XSS attack where malicious code embedded in comment fields gets executed when other users browse the guestbook, potentially stealing cookies, session tokens, or redirecting users to malicious sites.
The operational impact of this vulnerability extends beyond simple script injection, as it creates a persistent security risk for TYPO3 websites that utilize the affected extension. Attackers can leverage this flaw to perform session hijacking, deface websites, steal sensitive information from authenticated users, or redirect victims to phishing sites. The vulnerability particularly affects websites where guestbook functionality is enabled and publicly accessible, making it a prime target for malicious actors seeking to exploit user trust. Additionally, the widespread use of TYPO3 in enterprise and government environments amplifies the potential damage, as compromised systems could lead to data breaches or unauthorized access to sensitive information.
Organizations should immediately upgrade to versions of the Modern Guestbook extension that address this vulnerability, as no reliable workarounds exist for the specific flaw. The recommended mitigation strategy involves implementing comprehensive input validation and output encoding mechanisms throughout the application's comment handling processes. Security teams should also deploy web application firewalls and implement content security policies to reduce the impact of potential exploitation attempts. This vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications, and represents a common pattern exploited under ATT&CK technique T1059.007 for command and scripting interpreter execution. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other TYPO3 extensions and ensure comprehensive protection against similar XSS vulnerabilities in the broader application ecosystem.