CVE-2012-5551 in MailChimp
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in the MailChimp module 7.x-2.x before 7.x-2.7 for Drupal allow remote attackers to inject arbitrary web script or HTML via vectors related to (1) a predictable "webhook URL key" and (2) improper sanitization of "Webhook variables from POST requests."
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Analysis
by VulDB Data Team • 02/24/2019
The CVE-2012-5551 vulnerability represents a critical cross-site scripting weakness in the MailChimp module for Drupal, specifically affecting versions 7.x-2.x prior to 7.x-2.7. This vulnerability exposes web applications to remote code execution risks through malicious injection attacks that can compromise user sessions and data integrity. The flaw stems from inadequate input validation and sanitization mechanisms within the module's handling of webhook communications and user-provided data.
The technical exploitation occurs through two primary vectors that together create a dangerous attack surface for malicious actors. The first vector involves a predictable webhook URL key that allows attackers to forge legitimate webhook requests and manipulate the module's behavior. This predictability undermines the security model designed to authenticate webhook communications, enabling unauthorized parties to inject malicious payloads. The second vector relates to improper sanitization of webhook variables extracted from POST requests, where the module fails to properly validate and escape user-supplied data before processing or rendering it within web responses. This dual weakness creates an environment where attackers can execute arbitrary JavaScript code in the context of affected users' browsers.
The operational impact of this vulnerability extends beyond simple data theft or session hijacking. When exploited, these XSS flaws can enable attackers to perform actions on behalf of authenticated users, potentially leading to complete account compromise and unauthorized access to sensitive marketing data. The vulnerability affects Drupal installations using the MailChimp module for email marketing automation, making it particularly dangerous for organizations that rely heavily on email campaigns and user engagement tracking. Attackers can leverage these flaws to inject malicious scripts that steal cookies, redirect users to phishing sites, or even modify campaign content, potentially causing significant reputational and financial damage.
Organizations should immediately implement mitigations including updating to the patched version 7.x-2.7 of the MailChimp module, which addresses the predictable webhook key generation and implements proper input sanitization. Security measures should also include implementing Content Security Policy headers to limit script execution, monitoring webhook traffic for suspicious activity, and conducting regular security audits of third-party modules. The vulnerability aligns with CWE-79, which catalogs cross-site scripting flaws, and represents a clear violation of secure coding practices outlined in the OWASP Top Ten. From an ATT&CK framework perspective, this vulnerability maps to T1566 (Phishing) and T1059 (Command and Scripting Interpreter) techniques, as attackers can use the XSS to deliver malicious payloads and establish persistent access through compromised user sessions. Organizations must also consider implementing web application firewalls to detect and block malicious webhook requests, while ensuring that all third-party Drupal modules undergo thorough security review before deployment.