CVE-2013-5964 in Flag module
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the administration page in the Flag module 7.x-3.x before 7.x-3.1 for Drupal allows remote authenticated users with the "Administer flags" permission to inject arbitrary web script or HTML via the flag title.
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Analysis
by VulDB Data Team • 02/27/2018
The CVE-2013-5964 vulnerability represents a critical cross-site scripting flaw within the Drupal Flag module version 7.x-3.x prior to 7.x-3.1. This vulnerability specifically targets the administration page of the module and affects remote authenticated users who possess the "Administer flags" permission. The flaw enables attackers to inject malicious web script or HTML code through the flag title field, creating a persistent security risk within Drupal-based web applications.
The technical implementation of this vulnerability stems from inadequate input sanitization within the Flag module's administrative interface. When administrators create or modify flag titles through the web-based administration page, the module fails to properly escape or validate user input before rendering it back to the browser. This lack of proper output encoding creates an XSS vector that can be exploited by malicious actors with appropriate permissions. The vulnerability is particularly concerning because it operates within the administrative context, where users already possess elevated privileges, making the potential impact significantly greater than typical frontend XSS flaws.
The operational impact of CVE-2013-5964 extends beyond simple script injection, as it provides attackers with the ability to execute arbitrary code within the context of authenticated administrator sessions. This capability enables attackers to perform actions such as creating or modifying flags, potentially leading to unauthorized data manipulation, privilege escalation, or even complete system compromise. The vulnerability's exploitation requires only the "Administer flags" permission, which is typically granted to trusted administrators, making it a particularly dangerous flaw in environments where administrative access is not adequately restricted. From a cybersecurity perspective, this vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications.
The attack surface for this vulnerability encompasses all Drupal installations using the Flag module version 7.x-3.x before 7.x-3.1 that have administrators with the required permissions. Attackers can leverage this flaw to establish persistent backdoors, steal session cookies, redirect users to malicious sites, or manipulate flag configurations to affect content delivery and user experience. The vulnerability also presents risks for data integrity and confidentiality, as attackers can potentially access sensitive information through manipulated flag behaviors or by injecting malicious scripts that capture user data.
Mitigation strategies for CVE-2013-5964 primarily involve immediate patching of the affected Flag module to version 7.x-3.1 or later, which includes proper input validation and output escaping mechanisms. Organizations should also implement additional security measures such as role-based access control reviews, regular security audits of administrative interfaces, and comprehensive input validation across all user-editable fields. The remediation process should include thorough testing of the patched module to ensure that no regressions occur in existing functionality. Security teams should also consider implementing web application firewalls and monitoring for suspicious activities related to flag administration, as outlined in the attack patterns documented within the MITRE ATT&CK framework for web application exploitation techniques.