CVE-2009-5096 in Flag Content
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the Flag Content module 5.x-2.x before 5.x-2.10 for Drupal allows remote attackers to inject arbitrary web script or HTML via the Reason parameter.
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Analysis
by VulDB Data Team • 01/18/2018
The CVE-2009-5096 vulnerability represents a critical cross-site scripting flaw within the Flag Content module for Drupal version 5.x-2.x prior to 5.x-2.10. This vulnerability specifically targets the handling of user input through the Reason parameter, creating an avenue for remote attackers to execute malicious web scripts or HTML code within the context of affected websites. The vulnerability exists within the web application's input validation mechanisms, where user-supplied data fails to be properly sanitized before being rendered back to other users. This particular flaw falls under the CWE-79 category of Cross-Site Scripting, which is classified as a fundamental weakness in web application security that allows attackers to inject client-side scripts into web pages viewed by other users.
The technical exploitation of this vulnerability occurs when an attacker submits malicious input through the Reason parameter of the Flag Content module functionality. When the vulnerable system processes this input without adequate sanitization or encoding, the malicious script becomes embedded within the web page content and executes in the browsers of unsuspecting users who subsequently view the flagged content. The attack vector is particularly dangerous because it leverages the trust relationship between the web application and its users, allowing the malicious code to run with the privileges of the victim's browser session. This vulnerability is classified under the ATT&CK technique T1566.001 for "Phishing with Social Engineering" and represents a classic example of how seemingly benign user interaction features can become attack vectors when proper input validation is absent.
The operational impact of CVE-2009-5096 extends beyond simple script execution, as the injected malicious code can perform various harmful actions including session hijacking, credential theft, redirection to malicious sites, data exfiltration, and modification of web page content. Attackers can leverage this vulnerability to steal user sessions, impersonate legitimate users, or manipulate the content displayed to other website visitors. The vulnerability particularly affects Drupal installations using the Flag Content module, which is commonly used for content flagging and user engagement features. Organizations running affected versions face significant risk of user data compromise and potential complete system infiltration if attackers successfully exploit this vulnerability. The security implications are compounded by the fact that the vulnerability affects the core functionality of content management systems, making it a prime target for automated exploitation tools and widespread attack campaigns.
Mitigation strategies for CVE-2009-5096 primarily focus on immediate patching and remediation efforts, with the most effective solution being the upgrade to Flag Content module version 5.x-2.10 or later, which contains the necessary security fixes. Organizations should implement comprehensive input validation and output encoding mechanisms to prevent similar vulnerabilities in other parts of their web applications. Additional protective measures include implementing Content Security Policy headers, regular security audits of third-party modules, and maintaining up-to-date vulnerability assessments of all installed Drupal modules. The vulnerability serves as a critical reminder of the importance of proper input sanitization and the necessity of keeping all web application components updated with the latest security patches. Security teams should also consider implementing web application firewalls and monitoring for suspicious input patterns to detect potential exploitation attempts before they succeed.