CVE-2012-5384 in WebCalendar
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in Craig Knudsen WebCalendar allow remote attackers to inject arbitrary web script or HTML via the (1) $name or (2) $description variables in edit_entry_handler.php, or (3) $url, (4) $tempfullname, or (5) $ext_users[] variables in view_entry.php, different vectors than CVE-2012-0846.
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Analysis
by VulDB Data Team • 03/15/2019
The CVE-2012-5384 vulnerability represents a critical cross-site scripting flaw in the WebCalendar application developed by Craig Knudsen, exposing users to significant security risks through multiple injection vectors. This vulnerability affects the web-based calendar application's handling of user input data, specifically targeting the edit_entry_handler.php and view_entry.php script files. The flaw stems from inadequate input validation and output encoding mechanisms that fail to properly sanitize user-supplied data before rendering it within web pages, creating persistent opportunities for malicious actors to execute arbitrary scripts in the context of affected users' browsers.
The technical implementation of this vulnerability manifests through several distinct attack vectors that exploit the application's insufficient data sanitization practices. In the edit_entry_handler.php file, the $name and $description variables serve as primary attack surfaces where unfiltered user input can be injected directly into the application's processing pipeline. Similarly, the view_entry.php file presents additional exposure points through the $url, $tempfullname, and $ext_users[] variables, which also fail to undergo proper input validation before being rendered in web responses. These vulnerabilities fall under the CWE-79 category of Cross-Site Scripting, specifically representing stored XSS attacks where malicious payloads are permanently stored within the application's database and executed whenever affected pages are accessed.
The operational impact of CVE-2012-5384 extends beyond simple data theft or defacement, as successful exploitation can enable attackers to establish persistent access to user sessions, steal authentication tokens, and potentially escalate privileges within the calendar application. Attackers can leverage these vulnerabilities to create malicious calendar entries containing JavaScript payloads that execute in the browsers of other users who view the affected entries. This creates a propagation mechanism where a single compromised entry can affect multiple users within the calendar system, potentially leading to widespread session hijacking, data exfiltration, and unauthorized administrative actions. The vulnerability also aligns with ATT&CK technique T1566.001 for initial access through malicious web content and T1071.001 for application layer protocol usage.
Mitigation strategies for CVE-2012-5384 should focus on implementing comprehensive input validation and output encoding mechanisms across all user-facing application components. Organizations must ensure that all user-supplied data undergoes strict sanitization before being processed or stored, utilizing proper HTML entity encoding for any data that will be rendered in web contexts. The application should implement a whitelist-based input validation approach that only accepts known good characters and patterns while rejecting potentially malicious content. Additionally, implementing Content Security Policy headers can provide an additional layer of protection against XSS attacks by restricting the sources from which scripts can be executed. Regular security audits and code reviews should be conducted to identify similar vulnerabilities in other application components, as this vulnerability demonstrates the importance of consistent security practices throughout the entire codebase. Organizations should also consider implementing web application firewalls and monitoring systems to detect and prevent exploitation attempts.