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CVE-2025-8293: Intl DateTime Calendar WordPress XSS Flaw

CVE-2025-8293 is a stored cross-site scripting vulnerability in the Intl DateTime Calendar WordPress plugin affecting versions up to 1.0.1. Authenticated attackers can inject malicious scripts. This article covers technical details, affected versions, impact assessment, and mitigation strategies.

Published:

CVE-2025-8293 Overview

CVE-2025-8293 is a Stored Cross-Site Scripting (XSS) vulnerability in the Intl DateTime Calendar plugin for WordPress. All versions up to and including 1.0.1 are affected. The vulnerability exists in the date parameter due to insufficient input sanitization and output escaping [CWE-79]. Authenticated attackers with Contributor-level access or higher can inject arbitrary JavaScript into pages. The injected scripts execute in the browser of any user who views the affected page.

Critical Impact

Authenticated contributors can persist malicious JavaScript in WordPress pages, enabling session theft, credential harvesting, and administrative account takeover when higher-privileged users view the content.

Affected Products

  • Intl DateTime Calendar plugin for WordPress (versions ≤ 1.0.1)
  • WordPress sites permitting Contributor-level registration
  • Any WordPress site with the plugin installed and activated

Discovery Timeline

  • 2025-08-16 - CVE-2025-8293 published to the National Vulnerability Database
  • 2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-8293

Vulnerability Analysis

The Intl DateTime Calendar plugin accepts user-controlled input through the date parameter without applying adequate sanitization or output escaping. When a contributor submits crafted input containing HTML or JavaScript payloads, the plugin stores the payload in the WordPress database. The payload later renders in page output without encoding, allowing execution in the browser context of any visitor. Because the injection is stored, exploitation persists across sessions and affects every subsequent page view.

The scope change reflected in the vulnerability metrics indicates the injected script executes outside the vulnerable plugin's security boundary. Administrators or editors viewing the affected page trigger the payload with their elevated session, enabling privilege escalation through credential theft or unauthorized administrative actions.

Root Cause

The root cause is a failure to apply WordPress sanitization functions such as sanitize_text_field() on input and esc_html() or esc_attr() on output. The date parameter should contain structured datetime data, but the plugin treats it as free-form text and renders it verbatim in generated markup.

Attack Vector

Exploitation requires an authenticated account with Contributor-level privileges or higher. The attacker crafts a post or page that includes a malicious date parameter value containing JavaScript. When any user, including administrators, accesses the affected page, the browser executes the injected script under the site's origin. See the Wordfence Vulnerability Report for additional technical context.

Detection Methods for CVE-2025-8293

Indicators of Compromise

  • Unexpected <script>, onerror, or onload attributes present in WordPress post_content or postmeta entries containing date field values
  • Outbound HTTP requests from browsers of authenticated administrators to unfamiliar domains after viewing content authored by contributors
  • New administrator accounts or modified user roles created shortly after a contributor submitted or updated a post

Detection Strategies

  • Audit database entries associated with the Intl DateTime Calendar plugin for HTML tags or JavaScript event handlers in the date parameter
  • Deploy a Web Application Firewall (WAF) rule that inspects POST bodies for script payloads targeting the plugin's endpoints
  • Enable WordPress activity logging to correlate content edits by contributor accounts with subsequent administrative session activity

Monitoring Recommendations

  • Monitor wp_posts and wp_postmeta tables for entries containing suspicious strings such as <script, javascript:, or onerror=
  • Track authentication events and role changes to detect account takeover following XSS execution
  • Review browser Content Security Policy (CSP) violation reports for inline script blocks originating from plugin-rendered pages

How to Mitigate CVE-2025-8293

Immediate Actions Required

  • Deactivate the Intl DateTime Calendar plugin until a patched version is confirmed available and installed
  • Audit all Contributor and higher accounts, removing accounts that are unused or unrecognized
  • Review recent posts and pages for injected script content and purge malicious entries from the database

Patch Information

No patched version has been published at the time of this writing. Monitor the official plugin page for updates beyond version 1.0.1. Apply the update as soon as the vendor releases a fixed release.

Workarounds

  • Restrict user registration and limit Contributor-level access to trusted individuals only
  • Enforce a strict Content Security Policy that disallows inline JavaScript execution on WordPress-rendered pages
  • Deploy a WAF ruleset that sanitizes or blocks HTML tags submitted through plugin form fields
  • Remove the plugin entirely if calendar functionality is not required for business operations
bash
# Disable the vulnerable plugin via WP-CLI
wp plugin deactivate intl-datetime-calendar
wp plugin delete intl-datetime-calendar

# Audit posts for injected script payloads
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%<script%' OR post_content LIKE '%onerror=%';"

Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.

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