CVE-2024-25916 in My Calendar Plugin
Summary
by MITRE • 03/15/2024
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Joseph C Dolson My Calendar allows Stored XSS.This issue affects My Calendar: from n/a through 3.4.23.
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Analysis
by VulDB Data Team • 03/15/2024
This vulnerability represents a critical cross-site scripting flaw classified as CWE-79 in the Common Weakness Enumeration catalog, specifically manifesting as a stored XSS attack vector within the My Calendar plugin for WordPress. The vulnerability occurs when user input is improperly sanitized during the web page generation process, allowing malicious scripts to be permanently stored on the server and subsequently executed in the context of other users' browsers. The affected version range spans from an unspecified beginning through version 3.4.23, indicating that all iterations within this timeline are susceptible to this particular weakness.
The technical implementation of this flaw involves the plugin's failure to properly validate and escape user-supplied data before rendering it within HTML output contexts. When attackers submit malicious payloads through input fields or parameters that are then processed and stored within the calendar entries, these scripts become persistent within the database. Upon subsequent page loads or calendar view rendering, the malicious code executes in the browsers of unsuspecting users who access the affected calendar pages, creating a stored XSS scenario that can persist long after the initial injection.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the capability to hijack user sessions, steal sensitive cookies, perform unauthorized actions on behalf of victims, and potentially escalate privileges within the WordPress environment. Attackers could leverage this weakness to access calendar data, modify entries, or even gain administrative control if users with elevated permissions interact with the compromised calendar. The persistence aspect of stored XSS makes this particularly dangerous as the malicious code remains active until explicitly removed from the database, allowing for prolonged exploitation periods.
Mitigation strategies should prioritize immediate patching of the My Calendar plugin to version 3.4.24 or later, which contains the necessary fixes for this vulnerability. Organizations should implement comprehensive input validation and output escaping mechanisms, ensuring all user-supplied data undergoes proper sanitization before being stored or rendered. Additional protective measures include implementing content security policies, using web application firewalls to monitor for suspicious payloads, and conducting regular security audits of WordPress plugins and themes. The vulnerability aligns with ATT&CK technique T1566.001 for initial access through malicious content and T1059.001 for command and scripting interpreter execution, making it a significant concern for organizations relying on WordPress platforms for calendar management and collaboration.