CVE-2005-0842 in eSupport
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in index.php in Kayako eSupport 2.3 allows remote attackers to inject arbitrary web script or HTML via the (1) _i or (2) _c parameter.
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Analysis
by VulDB Data Team • 08/01/2025
The vulnerability identified as CVE-2005-0842 represents a critical cross-site scripting flaw within Kayako eSupport version 2.3, specifically affecting the index.php script. This security weakness enables remote attackers to execute malicious web scripts or HTML code within the context of affected user sessions, fundamentally compromising the application's security posture and user data integrity. The vulnerability manifests through two distinct parameter injection points denoted as _i and _c, which serve as entry vectors for malicious payload delivery.
This XSS vulnerability operates by failing to properly sanitize or validate user input received through the specified parameters in the web application's request handling mechanism. When legitimate users navigate to affected pages with maliciously crafted parameters, the application processes these inputs without adequate filtering or encoding, allowing attacker-controlled scripts to be executed in the browser context of other users. The flaw resides in the application's failure to implement proper input validation and output encoding mechanisms, creating an environment where user-supplied data can be interpreted as executable code rather than benign text.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, data exfiltration, and redirection to malicious websites. Attackers can exploit this weakness to steal session cookies, potentially gaining unauthorized access to user accounts and administrative privileges within the eSupport system. The vulnerability affects the entire user base of the application, making it particularly dangerous as it can be exploited against any authenticated user without requiring special privileges or complex attack vectors. This makes it a prime target for widespread exploitation and demonstrates the critical importance of input validation in web applications.
Mitigation strategies for CVE-2005-0842 should focus on implementing comprehensive input sanitization and output encoding practices throughout the application's codebase. The most effective approach involves proper parameter validation using allowlists of acceptable characters and values, combined with HTML entity encoding of all user-supplied data before rendering in web pages. Organizations should also implement Content Security Policy headers to limit script execution contexts and employ web application firewalls to detect and block malicious payloads. This vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws, and represents a classic example of how inadequate input validation can lead to severe security consequences. From an ATT&CK framework perspective, this vulnerability maps to T1566, representing the initial access phase through malicious web content delivery, and T1071, covering application layer protocol usage for command and control communications. The remediation process should include comprehensive code review, implementation of secure coding practices, and regular security testing to prevent similar vulnerabilities from emerging in future versions of the application.