CVE-2010-2854 in Event Horizon
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in modfile.php in Event Horizon (EVH) 1.1.10, when magic_quotes_gpc is disabled, allow remote attackers to inject arbitrary web script or HTML via the (1) YourEmail and (2) VerificationNumber parameters, which are not properly handled in a forced SQL error message. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 01/02/2018
The vulnerability identified as CVE-2010-2854 represents a critical cross-site scripting flaw within the Event Horizon content management system version 1.1.10. This security weakness specifically targets the modfile.php component and manifests when the PHP configuration parameter magic_quotes_gpc is disabled, creating an environment where malicious input can be executed without proper sanitization. The vulnerability affects two distinct parameter fields: YourEmail and VerificationNumber, which are processed within a forced SQL error message context, making the attack vector particularly insidious as it leverages legitimate system error handling mechanisms to execute malicious code.
The technical exploitation of this vulnerability occurs through the improper handling of user-supplied input within SQL error messages, which creates a direct pathway for attackers to inject malicious scripts. When magic_quotes_gpc is disabled, PHP does not automatically escape special characters in GET, POST, and COOKIE data, leaving the application vulnerable to injection attacks. The forced SQL error message mechanism in modfile.php fails to properly sanitize or escape the input parameters, allowing attackers to craft malicious payloads that execute when the error message is rendered in the browser. This vulnerability directly maps to CWE-79, which defines cross-site scripting as the injection of malicious code into web applications, and specifically relates to CWE-89, which addresses SQL injection vulnerabilities that can lead to XSS exploitation.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with the capability to execute arbitrary web scripts and HTML content within the context of authenticated users' browsers. This can lead to session hijacking, credential theft, defacement of web content, and potentially full system compromise if users have administrative privileges. The forced SQL error message context creates a persistent attack surface where even seemingly benign user inputs can be weaponized, making the vulnerability particularly dangerous in environments where legitimate error messages are displayed to end users. Attackers can leverage this vulnerability to establish persistent backdoors, redirect users to malicious sites, or steal sensitive information from authenticated sessions.
Mitigation strategies for CVE-2010-2854 require immediate implementation of multiple defensive measures including input validation and sanitization, proper output encoding, and configuration hardening. The most critical immediate action involves enabling magic_quotes_gpc or implementing comprehensive input sanitization routines for all user-supplied data, particularly within error handling contexts. Organizations should implement proper parameterized queries to prevent SQL injection that could lead to XSS exploitation, while also ensuring that all error messages are properly sanitized before display. The use of Content Security Policy headers and proper HTML encoding of all dynamic content can significantly reduce the attack surface, while regular security audits and code reviews should be conducted to identify similar vulnerabilities in other components. Additionally, upgrading to a supported version of Event Horizon that addresses this vulnerability is essential, as the affected version 1.1.10 is no longer maintained and likely contains additional undiscovered security flaws that could be exploited in conjunction with this vulnerability.