CVE-2005-4327 in WebCal
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in Michael Arndt WebCal 1.11-3.04 allow remote attackers to inject arbitrary web script or HTML via the (1) function, (2) year, and (3) date parameters to webcal.cgi, (4) new calendar entries, and (5) notes for entries.
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Analysis
by VulDB Data Team • 11/30/2024
The vulnerability identified as CVE-2005-4327 represents a critical cross-site scripting flaw affecting Michael Arndt WebCal versions 1.11 through 3.04. This vulnerability resides within the webcal.cgi script which serves as the primary interface for calendar functionality in this web-based application. The flaw manifests through multiple attack vectors that collectively weaken the application's input validation mechanisms, creating opportunities for malicious actors to execute unauthorized code within the context of victim browsers.
The technical implementation of this vulnerability stems from insufficient sanitization of user-supplied input parameters within the webcal.cgi script. Attackers can exploit this weakness by manipulating five distinct parameter fields including function, year, date, new calendar entries, and notes for entries. These parameters receive direct user input without proper validation or encoding, allowing malicious scripts to be injected and subsequently executed when other users view the affected calendar entries. The vulnerability operates at the application layer and specifically targets the web application's handling of dynamic content generation, making it particularly dangerous in multi-user environments where calendar data is shared.
The operational impact of CVE-2005-4327 extends beyond simple data theft or defacement, as it enables attackers to establish persistent footholds within victim environments. When exploited, the XSS vulnerabilities can facilitate session hijacking attacks, allowing unauthorized access to calendar data and potentially leading to broader system compromise. The vulnerability's presence in calendar entry creation and note fields means that even legitimate users can unknowingly become vectors for attack when creating or viewing calendar content. This creates a particularly insidious threat model where the application itself becomes a tool for delivering malicious payloads to unsuspecting users.
From a cybersecurity framework perspective, this vulnerability maps directly to CWE-79 which specifically addresses cross-site scripting flaws in web applications. The attack surface encompasses multiple entry points within the calendar application, aligning with ATT&CK technique T1566.001 for initial access through malicious web content. Organizations utilizing affected WebCal versions face significant risk of credential theft, data exfiltration, and potential lateral movement within their network environments. The vulnerability demonstrates poor input validation practices and highlights the critical importance of implementing comprehensive sanitization measures for all user-supplied data in web applications.
Mitigation strategies for CVE-2005-4327 require immediate implementation of proper input sanitization and output encoding mechanisms. System administrators should upgrade to patched versions of WebCal or implement comprehensive parameter validation that filters out malicious script content before processing user input. Additionally, implementing Content Security Policy headers and using proper HTML encoding techniques can significantly reduce the attack surface. Organizations should also consider implementing web application firewalls to detect and block malicious payloads attempting to exploit this vulnerability. Regular security assessments and input validation reviews should be conducted to prevent similar vulnerabilities from emerging in other application components. The remediation process must include thorough testing to ensure that all parameter fields properly sanitize user input while maintaining application functionality.