CVE-2025-52131 in Mocca Calendar
Summary
by MITRE • 08/03/2025
The Mocca Calendar application before 2.15 for XWiki allows XSS via the background or text color field.
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Analysis
by VulDB Data Team • 08/05/2025
The vulnerability identified as CVE-2025-52131 affects the Mocca Calendar application version 2.14 and earlier within the XWiki platform, representing a cross-site scripting weakness that could enable malicious actors to execute arbitrary code within the context of a victim's browser. This flaw specifically manifests in the application's handling of user input within the background or text color fields, which are typically used for customizing calendar event appearances. The vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is classified as a critical security concern in web applications.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding within the calendar application's user interface components. When users specify background or text color values for calendar events, the application fails to properly sanitize these inputs before rendering them in the HTML output. This omission creates an opportunity for attackers to inject malicious script code that will execute when other users view the affected calendar entries. The flaw is particularly concerning because it operates on fields that are inherently part of the application's user customization features, making it difficult to predict or prevent through traditional security measures.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with a potential foothold for more sophisticated attacks within the XWiki environment. An attacker who successfully exploits this vulnerability could potentially steal session cookies, redirect users to malicious sites, or perform actions on behalf of authenticated users. The attack vector requires minimal user interaction, as the malicious scripts execute automatically when calendar entries are displayed, making this vulnerability particularly dangerous in environments where multiple users interact with shared calendar systems. This weakness could facilitate unauthorized access to sensitive calendar data, compromise user privacy, and potentially enable further exploitation within the broader XWiki platform.
Organizations utilizing the Mocca Calendar application should immediately implement mitigations including input validation for all color field parameters, proper HTML encoding of user-supplied content before rendering, and application updates to version 2.15 or later where this vulnerability has been addressed. Security teams should also consider implementing content security policies to limit script execution capabilities within calendar interfaces and conduct regular security assessments of web applications to identify similar input validation gaps. The vulnerability demonstrates the importance of comprehensive input sanitization in web applications and aligns with ATT&CK technique T1203, which covers exploitation of web application vulnerabilities for unauthorized access. Additionally, this issue highlights the necessity of following secure coding practices as outlined in OWASP Top 10 and the importance of regular security patch management to prevent exploitation of known vulnerabilities in widely used web applications.