CVE-2005-2882 in phpCommunityCalendar
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in phpCommunityCalendar 4.0.3, and possibly earlier versions, allow remote attackers to inject arbitrary web script or HTML via the LocationID parameter to (1) thankyou.php or (2) day.php, font parameter to (3) calDaily.php, (4) calMonthly.php, (5) calMonthlyP.php, (6) calWeekly.php, (7) calWeeklyP.php, (8) calYearly.php, (9) calYearlyP.php, (10) day.php, or (11) week.php, or (12) CeTi, (13) Contact, (14) Description, (15) ShowAddress parameter to event.php, and other attack vectors.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/09/2019
The vulnerability identified as CVE-2005-2882 represents a critical cross-site scripting flaw affecting phpCommunityCalendar version 4.0.3 and potentially earlier releases. This vulnerability stems from inadequate input validation and output encoding mechanisms within the calendar application's web interface. The flaw allows remote attackers to inject malicious scripts into web pages viewed by other users, creating a persistent threat vector that can be exploited across multiple endpoints within the application's codebase. The vulnerability affects core calendar functionality and user interaction points, making it particularly dangerous for web applications that rely on user-generated content or dynamic parameter handling.
The technical implementation of this vulnerability occurs through multiple attack vectors that exploit the application's failure to sanitize user-supplied input before rendering it in web responses. Specifically, the LocationID parameter in thankyou.php and day.php accepts unvalidated input that gets directly embedded into HTML output without proper encoding or filtering. Similarly, the font parameter across multiple calendar display scripts including calDaily.php, calMonthly.php, and various other calendar views fails to validate or sanitize user input before incorporating it into the rendered HTML. Additionally, event.php contains vulnerabilities through CeTi, Contact, Description, and ShowAddress parameters that all suffer from the same input validation deficiencies. These multiple entry points significantly expand the attack surface and increase the likelihood of successful exploitation.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform session hijacking, deface web pages, steal sensitive user information, or redirect users to malicious websites. The persistent nature of XSS vulnerabilities means that once exploited, malicious scripts can execute in the context of authenticated users' browsers, potentially leading to privilege escalation or unauthorized access to sensitive calendar data. Attackers can craft malicious URLs containing script payloads that, when clicked by victims, will execute the injected code in the victim's browser context. This creates a particularly dangerous scenario for calendar applications that may contain personal or business-sensitive information, as the vulnerability can be leveraged to compromise user sessions and access confidential data stored within the calendar system.
The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications, and follows the ATT&CK framework's technique T1566 for initial access through malicious web content. Organizations using affected versions of phpCommunityCalendar should immediately implement input validation and output encoding measures, including implementing proper HTML entity encoding for all user-supplied input before rendering in web contexts. The recommended mitigation strategies include applying the latest security patches from the vendor, implementing web application firewalls to detect and block malicious payloads, and conducting thorough input validation across all user-facing parameters. Additionally, developers should adopt secure coding practices that enforce strict parameter validation and implement proper output encoding mechanisms to prevent script execution in web contexts. The vulnerability demonstrates the critical importance of input sanitization in web applications and highlights the need for comprehensive security testing of user interaction points in calendar and scheduling software systems.