CVE-2011-4924 in Zope
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Zope 2.8.x before 2.8.12, 2.9.x before 2.9.12, 2.10.x before 2.10.11, 2.11.x before 2.11.6, and 2.12.x before 2.12.3, 3.1.1 through 3.4.1. allows remote attackers to inject arbitrary web script or HTML via vectors related to the way error messages perform sanitization. NOTE: this issue exists because of an incomplete fix for CVE-2010-1104
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/27/2024
The CVE-2011-4924 vulnerability represents a critical cross-site scripting flaw in the Zope application server platform that affects multiple version ranges spanning from 2.8.x through 3.4.1. This vulnerability specifically targets the error message handling mechanisms within Zope's sanitization processes, creating a pathway for remote attackers to execute malicious web scripts or HTML code within the context of affected applications. The flaw emerged as an incomplete remediation of a previous vulnerability identified as CVE-2010-1104, demonstrating how security fixes can sometimes introduce new attack vectors when not thoroughly implemented. The vulnerability operates by exploiting the way Zope processes and displays error messages, particularly when these messages contain user-supplied input that should have been properly sanitized but was not. This creates a persistent security gap that allows attackers to inject malicious payloads through various input vectors that ultimately manifest in error page displays.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within Zope's error handling subsystem. When Zope encounters errors during processing, it generates error messages that may contain user-provided data without sufficient sanitization before rendering them in web pages. This creates an environment where attacker-controlled input can be embedded directly into error messages and subsequently executed by unsuspecting users who view these pages. The flaw manifests across multiple Zope versions because the underlying sanitization logic was not properly addressed in the previous patch for CVE-2010-1104, leaving residual vulnerabilities in the error message processing pipeline. Attackers can leverage this weakness by crafting malicious input that, when processed by the application, generates error messages containing their payload, which then executes in the browser context of users viewing these error pages. This vulnerability operates at the application layer and can be exploited through various means including form submissions, URL parameters, or any input field that triggers error conditions within the Zope application.
The operational impact of CVE-2011-4924 extends beyond simple script execution, as it can enable attackers to perform a wide range of malicious activities including session hijacking, data theft, and redirection to malicious sites. When users encounter error pages that contain injected scripts, these scripts can access cookies, session tokens, and other sensitive information that the user's browser maintains for the affected application. This creates a significant risk for applications that handle sensitive data or user authentication, as attackers can potentially escalate their privileges or gain unauthorized access to protected resources. The vulnerability is particularly dangerous because it can be triggered through normal application usage patterns, making it difficult to detect and prevent. Organizations using affected Zope versions face potential data breaches, unauthorized access to user accounts, and compromise of application integrity, as the injected scripts can modify application behavior or redirect users to phishing sites. The widespread nature of Zope deployments across various organizations means that this vulnerability could affect numerous applications, from content management systems to enterprise applications.
Mitigation strategies for CVE-2011-4924 require immediate implementation of version upgrades to patched releases of Zope, specifically versions 2.8.12, 2.9.12, 2.10.11, 2.11.6, and 2.12.3 or later. Organizations should also implement robust input validation and sanitization at multiple layers of their applications, ensuring that all user-supplied data is properly escaped before being processed or displayed. Network-level protections such as web application firewalls can provide additional defense-in-depth measures, though these are not substitutes for proper application-level fixes. Security teams should conduct comprehensive vulnerability assessments to identify all applications running affected Zope versions and ensure proper patching procedures are followed. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications, and it maps to ATT&CK technique T1190 which covers exploitation of vulnerabilities in web applications. Organizations should also implement proper error handling procedures that prevent user input from being directly embedded in error messages without adequate sanitization, and consider implementing content security policies to limit the execution of unauthorized scripts within their applications. Regular security testing and monitoring should be implemented to detect similar issues that may arise from incomplete security fixes.